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)

Since glycogen accumulates in the placenta in diabetes and does not appear to be susceptible, in general, to the effect of fasting, the capacity of catecholamines to elicit glycogenolysis was investigated in non-diabetic and diabetic rats. Injection of epinephrine or isoproterenol caused a decrease in placental glycogen within 20 min in non-diabetic, 20 day pregnant rats, in association with the rise in serum glucose and lactate. Incubation with isoproterenol induced glycogenolysis in placental slices from non-diabetic and diabetic rats, nearly commensurate with lactate production. This effect of isoproterenol was concentration dependent and of similar magnitude in non-diabetic and diabetic rat placentas. Glucagon was ineffective in inducing placental glycogenolysis in vivo or in vitro. Protracted stimulation of the catecholamine receptor by the administration of cholera toxin effected a pronounced decrease in placental glycogen, percentagewise higher in diabetic than non-diabetic rats. These results show that placental glycogen is amenable to mobilization by hormonal stimuli effecting phosphorylase activation.
Placenta
PMID:Mobilization of placental glycogen in diabetic rats. 214 54

A protein that inactivates the immunoreactivity of GnRH, TRH and angiotensin II has been isolated from human term placentae. Only in the presence of DTT, a sulphydryl agent, are OXY and SRIF also inactivated by this protein. However, it is without effect on CRF, hCS, or hCG. It also inhibits the biological activity of GnRH, i.e. its ability to stimulate pituitary LH and FSH. The ability of this protein to inactivate GnRH, TRH or angiotensin II can be inhibited by various peptidase inhibitors. Thus, we have postulated that it is a chorionic peptidase, specific for these peptides, and herein called chorionic peptidase-1 (C-ase-1). Isolation of this protein, C-ase-1, has been effected using permeation, ion exchange and affinity chromatography. As estimated by SDS-PAGE and HPLC analyses, C-ase-1 has an apparent molecular weight of 58,000. It is proposed that C-ase-1 may be an important chorionic regulator of GnRH, TRH and angiotensin II levels during pregnancy.
Placenta
PMID:Characterization and purification of a placental protein that inactivates GnRH, TRH and angiotensin II. 250 48

The potential contributions of placental extraction and degradation to glucoregulatory hormone turnover in late pregnancy were assessed by measuring arteriovenous differences for glucose, insulin, glucagon and human placental lactogen (hPL) across the uterine and fetal circulation in ten pregnant women at the time of elective caesarean section. The observations were made during stable conditions of euglycaemia; values for maternal arterial glucose, insulin, glucagon and hPL were 78.8 +/- 5.0 mg/dl, 10.1 +/- 2.1 microU/ml, 72.0 +/- 8.5 pg/ml and 5.18 +/- 0.59 micrograms/ml, respectively. The glucose decrements observed consistently across the uterus and fetus indicated uptake by the placenta and fetus, and in the maternal circulation the arterial-uterine vein increment for hPL was 2.10 +/- 0.44 micrograms/ml. However, within the limits of analytical accuracy, no significant gradient could be demonstrated for insulin across the uterine (maternal) or umbilical (fetal) circulations. A small (8.5 per cent) but significant arteriovenous difference for glucagon was observed across the uterus but none was found on the fetal side of the placenta. The findings indicate that detectable gradients for insulin cannot be demonstrated under basal conditions of metabolism and at normal rates of placental blood flow. The results do not exclude the possibility of more significant extraction ratios under other physiological conditions or at higher concentrations of glucoregulatory hormones.
Placenta
PMID:Transplacental arteriovenous gradients for glucose, insulin, glucagon and placental lactogen during normoglycaemia in human pregnancy at term. 390 31