Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with classical Albright's pseudohypoparathyroidism was investigated because of oligomenorrhoea. Hypo-oestrogenism was associated with elevated basal gonadotrophin values [mean basal serum LH and FSH were 272 +/- 84 (SD) ng/ml and 593 +/- 83 ng/ml, resplectively (normal less than or equal to 220 and less than or equal to 400, respectively)]. The response to gonadotrophin releasing hormone (Gn-RH) was exaggerated, with maximal LH and FSH increments of 1688 and 458 ng/ml, respectively. These results and the findings on ovarian biopsy were compatible with partial ovarian resistance to gonadotrophins. This resistance could be overcome by administration of human menopausal gonadotrophins. This is the first evidence for gonadotrophin resistance in pseudohypoparathyroidism. The plasma cyclic adenosine-3',5'-monophosphate response to glucagon administration by two different protocols was about 70% that of normal control subjects. Other endocrine glands whose responses to hormones are mediated via the adenylate cyclase system evidenced minor abnormalities of questionable significance. This indirect evidence is compatible with a more extensive defect in the adenylate cyclase system in pseudohypoparathyroidism than has hitherto been suspected.
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PMID:Partial gonadotrophin-resistance in pseudohypoparathyroidism. 20 40

A case of pseudohypoparathyroidism has been investigated. Indirect evidence allows to eliminate a defect of renal 1 alpha-hydroxylase as the determining factor of this condition. Similarly, the increased size of the mean surface area of the cross-section of periosteocytic lacunae, as determined on decalcified sections of bone obtained by transiliac biopsy, shows the osteocytes to be sensitive to the endogenous PTH, discarding cAMP response to PTH in bone as a prerequisite for PTH action on bone. The authors conclude from these data and from previous experiments that the defect of parathyroid function in this condition probably relates to the existence of an abnormal PTH molecule and/or metabolism and/or interaction with the receptors sites. The endocrine function was studied as well. Prediabetes was demonstrated, as well as primary latent hypothyroidism (TRH test). Prolactin release could not be stimulated by TRH, levodopa, metoclopramide, chlorpromazine and insulin hypoglycemia. The latter produced a normal release of ACTH (as ascertained by plasma cortisol levels) and GH, and possibly a sluggish response of glucagon and gastrin. There was a deficiency of urinary concentration upon restriction of fluid intake. This was only partially corrected by ADH administration.
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PMID:[Physio-pathology of pseudohypoparathyroidism (author's transl)]. 22 97

Pseudohypoparathyroidism is a complex disorder of renal resistance to parathyroid hormone the mechanism of which is unclear. It is often associated with skeletal abnormalities and there may also be other hormonal defects. This is an extensive endocrinological investigation of five of six affected members in two generations of one family. The phenotypic variability of the syndrome is explored: four members had hypothyroidism; two had abnormal gonadal function; all five had abnormal prolactin response to TRH; one had abnormal hepatic response to glucagon infusion. All had normal hypothalamic-pituitary-adrenal axes, renal responsiveness to vasopressin and growth hormone responses to a variety of stimuli. Special note is made of oral pathology, and evidence of platelet aggregation abnormalities is presented which has not previously been described in the syndrome.
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PMID:Pseudohypoparathyroidism: its phenotypic variability and associated disorders in a large family. 204 19

To examine the effect of glucagon in vivo on renal formation and excretion of cAMP, clearance studies were performed in patients with hypoparathyroidism and in parathyroidectomized rats. Four patients with idiopathic hypoparathyroidism and 2 patients with pseudohypoparathyroidism were studied during an intravenous glucagon infusion (20 micrograms/kg body weight). In all patients, glucagon induced a significant increase in nephrogenous cAMP and a 2- to 3-fold increase in fractional excretion of phosphate. The average increase in nephrogenous cAMP was from a baseline of 784 +/- 229 to 18,748 +/- 3,842 pmol/100 ml glomerular filtrate (GF) (p less than 0.01) and occurred 30-60 min after the beginning of the glucagon infusion. The effect of intravenous glucagon, given as a bolus, was further examined in parathyroidectomized rats. Glucagon elicited a significant increase in the urinary excretion of the nucleotide. The excreted cAMP was compared with its filtered load for each urine collection period. In the first two collections, 0-15 and 15-30 min, the filtered load of cAMP was higher than its urinary excretion. During the following periods, 30-90 min, the excreted urinary cAMP exceeded by far its filtered load, suggesting a net nephrogenous contribution to the excretion of the nucleotide. Infusion of exogenous cAMP to parathyroidectomized rats induced significant increments in the filtered load and urinary excretion of the nucleotide. Tubular secretion of extrarenal cAMP could not be detected during the cAMP infusion. These results provide evidence supporting in vivo a possible parathyroid-independent formation of nephrogenous cAMP after glucagon administration, in men and in rats. The glucagon-induced increase in nephrogenous cAMP seems to account, at least partly, for some of the renal actions of this hormone.
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PMID:Effect of intravenous glucagon on the urinary excretion of adenosine 3',5'-monophosphate in man and in rats. Evidence for activation of renal adenylate cyclase and formation of nephrogenous cAMP. 285 Apr 59

In six patients with pseudohypoparathyroidism (PHP) who were deficient in guanine nucleotide-binding stimulatory protein (Ns) activity, the response to endogenous arginine vasopressin (AVP) was tested during water deprivation. Hourly plasma osmolality (Posm), urinary osmolality (Uosm), and urinary AVP (UAVP) values were compared to those in normal subjects. The Uosm vs. Posm and the UAVP vs. Uosm relationships of the patients were all within the normal range. Four patients with Ns-deficient PHP were subjected to maintained water loads and infused with AVP at three different rates for 1 h each to assess their responses to exogenous AVP. Urinary volume and osmolality values from the final 30 min of each infusion rate were measured. All volume values except 1 were within 1.6 SD of normal, and all osmolality values except 1 were within 1.1 SD of normal. In conclusion, these studies indicate that these six patients with Ns-deficient PHP are not resistant to the antidiuretic (cAMP-mediated) action of endogenous or exogenous AVP, in contrast to the previously documented resistance of patients with Ns-deficient PHP to the actions of PTH, TSH, glucagon, and gonadotropins.
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PMID:Evidence for normal antidiuretic responses to endogenous and exogenous arginine vasopressin in patients with guanine nucleotide-binding stimulatory protein-deficient pseudohypoparathyroidism. 299 79

Single or graded doses of glucagon (Eli Lilly) were given to patients with pseudohypoparathyroidism (PsHP) type I to examine the possible presence of hormone resistance. The doses of glucagon ranged from 0.25-15 micrograms/kg. The following individuals were studied: 13 normal subjects, 5 patients with low erythrocyte N-protein activity (PsHP type Ia), and 7 patients with normal erythrocyte N-protein activity (PsHP type Ib). Two additional patients with treated primary hypothyroidism who were relatives of a patient with PsHP type Ib were also studied. The patients with PsHP type Ia had blunted plasma cAMP responses to all glucagon doses. In contrast, the patients with PsHP type Ib had normal cAMP responses to glucagon infusion. However, the 2 relatives of the patient with PsHP type Ib had clearly decreased cAMP responses to glucagon infusion; both had normal renal responses to PTH and were clinically and biochemically euthyroid at the time of study. Glucose responses to glucagon were normal in both PsHP groups; the glucose response per unit cAMP response was slightly, but not significantly, enhanced in PsHP type Ia patients. Glucagon resistance appears to be a common finding in patients with PsHP type Ia, but not in those with PsHP type Ib. However, the observation of reduced glucagon responsivity in association with familial hypothyroidism in a kindred with PsHP type Ib suggests the possibility that this disorder may also cause disturbances in several hormone systems.
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PMID:Responses to glucagon infusion in pseudohypoparathyroidism. 302 20

A case of a 33 year old man with type I of pseudohypoparathyroidism associated with hypercalcitoninaemia and deficiency of prolactin and growth hormone is reported. The diagnosis of pseudohypoparathyroidism was made by recognition of the classic skeletal signs of Albright's osteodystrophy and confirmed by an infusion test with parathyroid hormone, which revealed a lack of both a cyclic AMP and phospaturic response. By investigation of the endocrine status the function of the pituitary/thyroid and pituitary/testis axes as well as the adrenal cortex was observed to be normal. The basal prolactin concentration was however, lower than normal and a lack of response in the growth hormone level in two glucagon tests was observed. Furthermore the basal calcitonin level was higher than normal and by provacation with pentagastrine the calcitonin secretion was very high despite an only slightly decreased serum calcium level. By operation the thyroid gland was normal and by light microscopy of a biopsy no signs of medullary carcinoma was observed. No good explanation for the high calcitonin basal level and secretion was found.
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PMID:Pseudohypoparathyroidism associated with hypercalcitoninaemia. 735 65

Albright hereditary osteodystrophy is caused by heterozygous inactivating mutations in GNAS, a gene that encodes not only the alpha-chain of Gs (Galphas), but also NESP55 and XLalphas through use of alternative first exons. Patients with GNAS mutations on maternally inherited alleles are resistant to multiple hormones such as PTH, TSH, LH/FSH, GHRH, and glucagon, whose receptors are coupled to Gs. This variant of Albright hereditary osteodystrophy is termed pseudohypoparathyroidism type 1a and is due to presumed tissue-specific paternal imprinting of Galphas. Previous studies have shown that mice heterozygous for a targeted disruption of exon 2 of Gnas, the murine homolog of GNAS, showed unique phenotypes dependent on the parent of origin of the mutated allele. However, hormone resistance occurred only when the disrupted gene was maternally inherited. Because disruption of exon 2 is predicted to inactivate Galphas as well as NESP55 and XLalphas, we created transgenic mice with disruption of exon 1 to investigate the effects of isolated loss of Galphas. Heterozygous mice that inherited the disruption maternally (-m/+) exhibited PTH and TSH resistance, whereas those with paternal inheritance (+/-p) had normal hormone responsiveness. Heterozygous mice were shorter and, when the disrupted allele was inherited maternally, weighed more than wild-type littermates. Galphas protein and mRNA expression was consistent with paternal imprinting in the renal cortex and thyroid, but there was no imprinting in renal medulla, heart, or adipose. These findings confirm the tissue-specific paternal imprinting of GNAS and demonstrate that Galphas deficiency alone is sufficient to account for the hormone resistance of pseudohypoparathyroidism type 1a.
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PMID:A mouse model of albright hereditary osteodystrophy generated by targeted disruption of exon 1 of the Gnas gene. 1609 56

Albright hereditary osteodystrophy (AHO) is a genetic disorder caused by heterozygous inactivating mutations in GNAS, the gene that encodes the alpha-chain of Gs (G alpha s). This syndrome is associated with short stature, obesity, brachydactyly, and subcutaneous ossifications. Patients with GNAS mutations on maternally-inherited alleles are resistant to multiple G-protein-coupled hormones, including parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), luteinizing hormone/follicle-stimulating hormone (LH/FSH), and glucagon. This variant of AHO, termed pseudohypoparathyroidism (PHP) type 1a, is due to tissue-specific paternal imprinting of G alpha s. We investigated whether patients with PHP type 1a exhibited evidence of resistance to growth hormone releasing hormone (GHRH) (1), another hormone requiring G alpha s function. In addition, G alpha s transcripts are imprinted in the pituitary somatotrophs responsible for growth hormone (GH) secretion which could thereby influence GHRH-dependent stimulation of somatotrophs. We therefore hypothesized that patients with PHP type 1a may be GH deficient which could contribute to the obesity and short stature in this condition. We found that GH deficiency is common in PHP type 1a (69%) with a prevalence that is much greater than in the general population (0.03%). We propose that GH status be evaluated in all patients with this condition. Treatment with recombinant GH could lead to improvements in height in children, as well as other physical (eg, obesity, hyperlipidemia, osteoporosis, reduced renal function) and psychological (fatigue and diminished sense of well-being) parameters in GH-deficient PHP type 1a patients of all ages.
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PMID:Short stature, obesity, and growth hormone deficiency in pseudohypoparathyroidism type 1a. 1667 31

We report a boy with pseudohypoparathyroidism (PHP), hypothyroidism and low growth hormone (GH) values with no response to growth hormone releasing hormone (GHRH). He presented at age 17 mo because of developmental delay. He had the typical features (short stature, obesity, round face, brachydactyly) of Albright's hereditary osteodystrophy (AHO) and the biochemical profile of PHP; low serum calcium and high phosphate, raised parathormone (PTH) values and lack of response of urinary phosphate and cyclic AMP to PTH administration. The serum total thyroxine value (T4) was 37.32 nmol/L and the thyroid stimulating hormone (TSH) 29 mU/L. Peak GH values during two provocative tests (Glucagon, L-Dopa) were <2.5 microg/L and <1.7 microg/L, respectively, while following GHRH administration the maximum GH value was 0.2 microg/L. The IGFI value was 65 ng/ml and rose to 253 ng/ml after GH administration for three days. This boy had PTH and TSH receptor defect and we speculate that he also has GHRH receptor defect.
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PMID:Pseudohypoparathyroidism type Ia and growth hormone deficiency. Growth hormone releasing hormone receptor defect? 1701 38


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