Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Central neural activity was assessed by measuring relative cytochrome oxidase (CO) activity in the ventromedial nucleus (VMN; thermogenesis regulation), the parvocellular paraventricular nucleus (PVN; feeding regulation), and the magnocellular PVN (secretion of vasopressin and oxytocin) in 10 age-matched pairs of 39- to 42-day-old Zucker rats. When obese (fa/fa) were compared to lean (Fa/Fa) rats, relative CO activity was significantly lower (approximately 10 percent) in the VMN and parvocellular PVN, but not in the magnocellular PVN. Cell diameters did not differ. To determine if there were corresponding differences in levels or release of hypothalamic monoamines, we compared 7 pairs of 90- to 94-day-old lean (Fa/?) and obese (fa/fa) rats at rest and after 2 h of 9 degrees C. Tissue punches from frozen PVN, VMN, and preoptic area (the latter being a site of thermosensitive units modulating VMN output) were assayed. In obese vs. lean noncold-exposed rats, we observed lower concentrations of: 5-hydroxyindoleacetic acid (5HIAA; metabolite of serotonin, 5HT) in the VMN; 3-methoxy-4-hydroxyphenylglycol (MHPG; metabolite of norepinephrine, NE) and NE + MHPG (index of total NE) in the preoptic area; and 3,4-dihydroxyphenylacetic acid (DOPAC; metabolite of dopamine, DA) in the PVN. Additionally, in the VMN, cold exposure resulted in: elevated concentrations of MHPG and MHPG + NE in both lean and obese rats; elevated concentrations of 5HT, 5HIAA, and 5HT + 5HIAA in obese rats, with no significant changes in these variables in lean animals; decreased ratio of 5HIAA/5HT in obese rats and increased ratio in leans. In the preoptic region, cold exposure led to increased concentrations of MHPG, NE + MHPG, 5HT, and 5HT + 5HIAA in obese but not lean rats. In the PVN, 5HT concentrations were increased in cold-exposed obese but not lean rats. Our data support the hypothesis that neuronal activity in obese rats differs from that of lean rats at rest and during cold exposure and suggest that several monoamine systems play a role in such differences.
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PMID:Neuronal activity in hypothalamic nuclei of obese and lean Zucker rats. 217 50

To investigate the role of dopamine (DA) in the secretion of progesterone and ovarian oxytocin (OT) in cattle in vivo and in vitro studies were performed. Luteal slices (middle stage of the luteal phase) were incubated-with five different amounts of DA (10(-3)-10(-7) M) and after 1, 2 and 4 h medium was collected for the progesterone and OT determination. The only 10(-5) M of DA enhanced OT medium concentrations (P < 0.05-0.001) and this response increased within duration of the incubation. The same dose of DA affected (P < 0.05-0.001) progesterone release during the incubation period. Next we wanted to study whether this mechanism will operate in conscious cattle. Mature heifers had cannulae inserted into the aorta abdominalis through the coccygeal artery for local infusion of saline or drugs, and into the jugular vein and the cava vena caudalis for the blood sample collection. In Experiment 2 six heifers on days 10-12 of the cycle received in Latin square design DA (8.4 micrograms/kg/min) for 2h, and they were pre-treated for 2 h with saline or for 1 h with droperidol (DROP; 1 microgram/kg/min) or with 4 micrograms/kg/min of beta-blocker, propranolol (PROP). DA increased (P < 0.05) OT plasma concentrations in all groups but secretion of progesterone was not changed (P > 0.05). DA decreased prolactin concentrations if pre-infused with saline and PROP and DROP diminished this effect of DA. Data suggest that DA affected OT release from both pituitary and from the ovary. Hence in Experiment 3 we wanted to elucidate whether DA caused those effects itself of after its conversion to the noradrenaline (NA). DA was given in six heifers as in Experiment 2 and blood samples were taken simultaneously from the vena cava and from the jugular vein. Within a few minutes from the start of DA infusion, large amount of DOPAC was measured by HPLC in blood. Next NA increase (P < 0.01) was observed in both veins but it was always higher (P < 0.05) in the vena cava. However, OT concentration in blood samples from both veins was not different (P > 0.05). Data indicate that DA can stimulate the secretory function of CL in cyclic heifers supposedly after its conversion to NA.
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PMID:Role of dopamine in the secretory function of corpus luteum in cattle. 887 3

Hatano high- and low-avoidance (in a two-way active avoidance task) animals (HAA and LAA, respectively) were successfully selected from a Sprague-Dawley rat population. Pup growth of both strains was dependent on the maternal strain in a cross-fostering study. To determine whether there are strain-specific differences between HAA and LAA in maternal care, both strains of dams were subjected to a test battery as measured by nest building, home cage behavior, pup retrieval, and milk ejection tests. In addition, changes in plasma concentrations of lactotropic and corticotropic hormones such as prolactin, ACTH, and corticosterone were examined during lactation. The test battery indicated that the dams of both strains built good nests and spent an identical amount of time with their offspring. However, LAA dams showed a prolonged latency time for pup retrieval and often left pups outside the nest until the end of the test period. LAA dams also showed a decreased amount of milk ejection, whereas no strain differences were observed in milk ejection after oxytocin treatment. During lactation, a lesser increase in plasma concentrations of prolactin and a greater increase in ACTH were found in LAA dams. There were no differences between the two strains in plasma concentrations of corticosterone. These results clearly demonstrated decreases in maternal behavior and milk ejection in LAA as compared to HAA dams. The present results also suggest that maternal motivation and mechanisms responsible for maternal hormones related to suckling are involved in the degree of pup growth.
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PMID:Maternal behavior, milk ejection, and plasma hormones in Hatano high- and low-avoidance rats. 1236 65

Social subordination in female macaques is imposed by harassment and the threat of aggression and produces reduced control over one's social and physical environment and a dysregulation of the limbic-hypothalamic-pituitary-adrenal axis resembling that observed in people suffering from psychopathologies. These effects support the contention that this particular animal model is an ethologically relevant paradigm in which to investigate the etiology of stress-induced psychological illness related to women. Here, we sought to expand this model by performing a discriminate analysis (DA) on 33 variables within three domains; behavioral, metabolic/anthropomorphic, and neuroendocrine, collected from socially housed female rhesus monkeys in order to assess whether exposure to social subordination produces a distinct phenotype. A receiver operating characteristic (ROC) curve was also calculated to determine each domain's classification accuracy. DA found significant markers within each domain that differentiated dominant and subordinate females. Subordinate females received more aggression, showed more submissive behavior, and received less of affiliation from others than did dominant females. Metabolic differences included increased leptin, and reduced adiponectin in dominant compared to subordinate females. Dominant females exhibited increased sensitivity to hormonal stimulation with higher serum LH in response to estradiol, cortisol in response to ACTH, and increased glucocorticoid negative feedback. Serum oxytocin, CSF DOPAC and serum PACAP were all significantly higher in dominant females. ROC curve analysis accurately predicted social status in all three domains. Results suggest that socially house rhesus monkeys represent a cogent animal model in which to study the physiology and behavioral consequences of chronic psychosocial stress in humans.
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PMID:Social subordination produces distinct stress-related phenotypes in female rhesus monkeys. 2224 48

The first 2 weeks of life in rats are known as the stress hyporesponsive period because stress responses in pups are diminished as compared to adult animals. However, it is considered a critical period in development in which infant rats are susceptible to environmental events, such as stressful stimuli and quality of maternal care received. These early life events have long-lasting effects, shaping a variety of outcomes, such as stress responsivity. This study investigated the effects of maternal care and sex differences on the response to an aversive stimulus in rat pups from high (HL) and low licking (LL) mothers. Plasma corticosterone, oxytocin, and central monoaminergic activity in 13-day-old rats submitted to cold stress were analyzed. Stress increased plasma corticosterone and marginally decreased hypothalamic dihydroxyphenylacetic acid/dopamine (DOPAC/DA) ratio. HL pups showed higher levels of plasma oxytocin than LL pups. The maternal effect was also detected in the hippocampus, in which 5-hydroxyindole-3-acetic acid/serotonin (5-HIAA/5-HT) ratio was increased in HL pups, independently of the sex and stress. Investigating the early life events is useful not only into understand the neurobiological and hormonal mechanisms underlying maternal and stressful influences on infant development into a healthy or psychopathological adult phenotype, but also to unveil the immediate outcomes on infancy.
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PMID:Stress in Neonatal Rats with Different Maternal Care Backgrounds: Monoaminergic and Hormonal Responses. 2526 Dec 16