ENDOCRINE EFFECTS ON THE HEPARIN-INDUCED LIPEMIA CLEARING ACTIVITY (LCA) OF RAT PLASMA

1955 ◽  
Vol 33 (4) ◽  
pp. 530-538 ◽  
Author(s):  
A. Cairns ◽  
P. Constantinides
Keyword(s):  
Sex Difference ◽  
Chronic Stress ◽  
Strong Evidence ◽  
Anterior Pituitary ◽  
Dosage Level ◽  
Rat Plasma ◽  
Female Gonad ◽  
Endocrine Effects ◽  
Long Period ◽  
Adrenal Enlargement

A study was made of the relationships of the gonads, the adrenal, and the thyroid to the "lipemia-clearing activity" (LCA) which appears in rat plasma following heparin injection. Strong evidence was obtained that the induction of LCA by heparin is controlled by the estrogenic secretion of the female gonad: Estradiol inhibited LCA; mature females displayed less LCA than mature males, the sex difference being absent in immature animals; ovariectomy and hypophysectomy accelerated LCA; anterior pituitary extracts inhibited it in the female but not in the male; progesterone, testosterone, and orchidectomy had no effect. The adrenal-LCA relationships were complex: Adrenalectomy accelerated LCA but the effects of injected steroids depended on the dosage level and on the duration of the treatment. Short lasting injections of small amounts of glucocorticoids inhibited LCA, the effect disappearing upon prolongation of treatment. By contrast, massive amounts of glucocorticoids accelerated LCA, whether given for a short or a long period of time. Chronic stress and ACTH had no effect, despite the induction of pronounced adrenal enlargement. Injected thyroxine inhibited LCA but surgical thyroidectomy did not affect it.

ENDOCRINE EFFECTS ON THE HEPARIN-INDUCED LIPEMIA CLEARING ACTIVITY (LCA) OF RAT PLASMA

1955 ◽  
Vol 33 (1) ◽  
pp. 530-538
Author(s):  
A. Cairns ◽  
P. Constantinides
Keyword(s):  
Sex Difference ◽  
Chronic Stress ◽  
Strong Evidence ◽  
Anterior Pituitary ◽  
Dosage Level ◽  
Rat Plasma ◽  
Female Gonad ◽  
Endocrine Effects ◽  
Long Period ◽  
Adrenal Enlargement

A study was made of the relationships of the gonads, the adrenal, and the thyroid to the "lipemia-clearing activity" (LCA) which appears in rat plasma following heparin injection. Strong evidence was obtained that the induction of LCA by heparin is controlled by the estrogenic secretion of the female gonad: Estradiol inhibited LCA; mature females displayed less LCA than mature males, the sex difference being absent in immature animals; ovariectomy and hypophysectomy accelerated LCA; anterior pituitary extracts inhibited it in the female but not in the male; progesterone, testosterone, and orchidectomy had no effect. The adrenal-LCA relationships were complex: Adrenalectomy accelerated LCA but the effects of injected steroids depended on the dosage level and on the duration of the treatment. Short lasting injections of small amounts of glucocorticoids inhibited LCA, the effect disappearing upon prolongation of treatment. By contrast, massive amounts of glucocorticoids accelerated LCA, whether given for a short or a long period of time. Chronic stress and ACTH had no effect, despite the induction of pronounced adrenal enlargement. Injected thyroxine inhibited LCA but surgical thyroidectomy did not affect it.

FURTHER STUDIES ON THE ENDOCRINE CONDITIONING OF THE HEPARIN-INDUCED LIPEMIA CLEARING ACTIVITY (LCA) IN THE RAT

1957 ◽  
Vol 35 (7) ◽  
pp. 503-510 ◽  
Author(s):  
P. Constantinides ◽  
A. Cairns ◽  
Y. So
Keyword(s):  
Dosage Level ◽  
Rat Plasma ◽  
Mild Stress ◽  
Qualitative Information ◽  
Endocrine Effects ◽  
Oil Emulsion ◽  
Intravenous Heparin ◽  
High Dosage Level ◽  
Males And Females ◽  
Low Dosage

The effects of various endocrines and of stress on the "lipemia clearing activity" (LCA) which is elicited in rat plasma by intravenous heparin injection were studied.High dosage cortisone accelerated LCA, but low dosage cortisone did not affect it. Severe catabolic stress accelerated LCA. Application of a single mild stress was ineffective, but the combination of two mild stressors accelerated LCA. ACTH had no influence on LCA, but adrenalectomy accelerated it. Stilbestrol inhibited LCA at both a low and a high dosage level, but there was no difference in LCA production between males and females or between estrous and diestrous females. Estrous females, however, displayed less LCA than ovariectomized females. Anterior pituitary extract inhibited LCA in females and hypophysectomy accelerated it in both sexes. A synthetic oil emulsion yielded the same qualitative information as lipemic plasma wherever it was used as a substrate for the clearing activity of postheparin plasma.Thus, with the exception of the effects of sex difference and low dosage cortisone, most of the previously reported endocrine effects on the LCA that follows subcutaneous heparin were also obtained when heparin was injected intravenously. The physiological significance of these findings is discussed.

FURTHER STUDIES ON THE ENDOCRINE CONDITIONING OF THE HEPARIN-INDUCED LIPEMIA CLEARING ACTIVITY (LCA) IN THE RAT

1957 ◽  
Vol 35 (1) ◽  
pp. 503-510 ◽  
Author(s):  
P. Constantinides ◽  
A. Cairns ◽  
Y. So
Keyword(s):  
Dosage Level ◽  
Rat Plasma ◽  
Mild Stress ◽  
Qualitative Information ◽  
Endocrine Effects ◽  
Oil Emulsion ◽  
Intravenous Heparin ◽  
High Dosage Level ◽  
Males And Females ◽  
Low Dosage

The effects of various endocrines and of stress on the "lipemia clearing activity" (LCA) which is elicited in rat plasma by intravenous heparin injection were studied.High dosage cortisone accelerated LCA, but low dosage cortisone did not affect it. Severe catabolic stress accelerated LCA. Application of a single mild stress was ineffective, but the combination of two mild stressors accelerated LCA. ACTH had no influence on LCA, but adrenalectomy accelerated it. Stilbestrol inhibited LCA at both a low and a high dosage level, but there was no difference in LCA production between males and females or between estrous and diestrous females. Estrous females, however, displayed less LCA than ovariectomized females. Anterior pituitary extract inhibited LCA in females and hypophysectomy accelerated it in both sexes. A synthetic oil emulsion yielded the same qualitative information as lipemic plasma wherever it was used as a substrate for the clearing activity of postheparin plasma.Thus, with the exception of the effects of sex difference and low dosage cortisone, most of the previously reported endocrine effects on the LCA that follows subcutaneous heparin were also obtained when heparin was injected intravenously. The physiological significance of these findings is discussed.

Effect of the anterior pituitary gland and gonads on enzyme components of the hepatic microsomal cytochrome P-450 system of male and female rats

1983 ◽  
Vol 96 (2) ◽  
pp. 259-267 ◽  
Author(s):  
B. Gillham ◽  
J. S. M. Hutchinson ◽  
M. B. Thorn
Keyword(s):  
Sex Difference ◽  
Anterior Pituitary ◽  
Testosterone Propionate ◽  
Specific Activity ◽  
Female Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Microsomal Cytochrome ◽  
Male And Female Rats ◽  
Cytochrome P 450

The concentration of cytochrome P-450 in microsomes prepared from the livers of mature female Wistar-derived rats was significantly lower than in mature males. This sex difference was abolished after hypophysectomy, when the concentration of the cytochrome in males and females was not significantly different from that in the intact male. A concentration of cytochrome P-450 characteristic of females was restored by two anterior pituitary transplants under the kidney capsule of hypophysectomized females; a partial 'feminization' occurred in similarly treated hypophysectomized males. A partial 'feminization' was also achieved by the administration of rat or sheep prolactin to hypophysectomized females. Unexpectedly, the administration of l-dihydroxyphenylalanine to normal females was without effect on cytochrome P-450, whereas in intact males 'feminization' resulted. Castration of adult rats resulted in the 'feminization' of cytochrome P-450, whereas ovariectomy was without effect. Administration of testosterone propionate for 10 days, either immediately after the operation or 14 weeks later to rats castrated when adult failed, however, to reverse the fall in cytochrome P-450. The establishment of a higher concentration of cytochrome P-450 in the liver of female rats could not be brought about by the administration of testosterone propionate, whether given as a single dose on the second day after birth or as a 10-day course of treatment after puberty or both. It is concluded that the sex difference in hepatic microsomal cytochrome P-450 is maintained by the release in the female of an anterior pituitary factor(s) that serves to depress its concentration. The factor(s) shows some of the characteristics of prolactin but the findings are not consistent with that hormone being responsible for all of the effects observed. The release of the factor(s) in the male may be inhibited by a compound of gonadal origin other than testosterone. A sex difference could not be 'imprinted' in the female by either neonatal and/or postpubertal testosterone treatment. The concentration of hepatic microsomal cytochrome b5 and the specific activity of NADPH-cytochrome c reductase were found not to be sex-dependent in the rats used. However, anterior pituitary factor(s) other than prolactin and growth hormone act to suppress partially the concentration of the former and to promote the specific activity of the latter in the endoplasmic reticulum of rat hepatocytes.

Asynchronous patterns of reproduction for the sympatric scallops Chlamys bifrons and Chlamys asperrima (Bivalvia: Pectinidae) in South Australia

2003 ◽  
Vol 54 (1) ◽  
pp. 77 ◽  
Author(s):  
C. A. Styan ◽  
A. J. Butler
Keyword(s):  
Strong Evidence ◽  
South Australia ◽  
Late Spring ◽  
Gonad Weight ◽  
Spawning Activity ◽  
Long Period ◽  
Indirect Sampling ◽  
A Minor ◽  
Gonad Condition

Patterns of spawning activity were assessed by monitoring gonad states over 2.5 years for Chlamys asperrima and Chlamys bifrons at two sites in Gulf St Vincent, South Australia. Chlamys asperrima appeared to have a minor spawning in June, followed by a major spawning starting in late August. In contrast, the gonads of C. bifrons were regressed only during winter and it appeared that C. bifrons spawned for a long period, from late spring (September) until early autumn (March). At one site where sampling was frequent, there was evidence of three series of C. bifrons spawning events during the summer of 1994/95 and at least two series of events during 1995/96. Build-up and decrease in gonad weight was quick, but there was strong evidence of serial spawning for both species. Subsequently, we once observed C. asperrima spawning in situ at Edithburgh Jetty, at a time when gonad weights had been decreasing in previous years, but also long after the time when peak gonad weights had usually occurred. Only patches within the population were seen spawning, with scallops not spawning observed less than 100 m away from those that were. Indirect sampling of gonad condition also suggested that spawning in C. bifrons at Largs Bay was not always synchronous among patches of scallops within a population, nor always between sexes within patches.

A further analysis of behavioral and endocrine effects of unpredictable chronic stress

1988 ◽  
Vol 43 (6) ◽  
pp. 789-795 ◽  
Author(s):  
E.L.Rodríguez Echandía ◽  
A.S. Gonzalez ◽  
R. Cabrera ◽  
L.N. Fracchia
Keyword(s):  
Chronic Stress ◽  
Endocrine Effects

Regulation of the TRH-like peptide pyroglutamyl-glutamyl-prolineamide in the rat anterior pituitary gland

1995 ◽  
Vol 145 (1) ◽  
pp. 43-49 ◽  
Author(s):  
J M M Rondeel ◽  
W Klootwijk ◽  
E Linkels ◽  
G A C van Haasteren ◽  
W J de Greef ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Sex Difference ◽  
Anterior Pituitary ◽  
Biological Significance ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Anterior Pituitary Gland ◽  
Female Rats ◽  
Male Rats ◽  
Rat Pituitary

Abstract TRH-like peptides share the N- and C-terminal amino acids with TRH (pGlu-His-Pro-NH2) but differ in the middle amino acid residue. One of them, pGlu-Glu-Pro-NH2 (<EEP-NH2; EEP) is present in the rat pituitary gland, but its biological significance is unknown. We investigated the localization and regulation of this tripeptide in the rat pituitary gland. To distinguish between TRH and EEP two antisera were used for RIA: specificity of antiserum 4319 for the TRH-like peptides pGlu-Phe-Pro-NH2 and EEP was equal to or greater than that for TRH, whereas antiserum 8880 is TRH-specific. Our RIA data showed the presence of a TRH-like peptide in the anterior pituitary gland (AP) and of TRH in the posterior pituitary gland (PP). The TRH-like peptide in the AP was identified on anion-exchange chromatography and subsequent HPLC as EEP. Pathophysiological conditions such as altered thyroid and adrenal status and suckling did not affect pituitary gland levels of EEP. In general, however, there is a clear sex difference: levels of EEP are higher in male than in female rats. In both sexes gonadectomy leads to a substantial two- to threefold rise in EEP levels, abolishing the sex difference. Testosterone administration to gonadectomized male rats normalizes levels of EEP again. Disulfiram, an inhibitor of the enzyme peptidylglycine α-amidating monooxygenase, reduced levels of EEP in the AP by approximately 50%. In conclusion: 1) the TRH-like peptide EEP is present in the AP, whereas TRH is confined to the PP, 2) levels of EEP in the AP are regulated by sex steroids, 3) EEP is actively amidated in the AP and thus seems to be produced from a glycine-extended progenitor sequence. Journal of Endocrinology (1995) 145, 43–49

Sign in / Sign up

Export Citation Format

Share Document