β-Endorphin regulates lordosis in female rats by modulating LH-RH release

Sirinathsinghji, D.J.S.; Whittington, P.E.; Audsley, A.R.; Fraser, Hamish M.

doi:10.1038/301062a0

Cited by 115 publications

(13 citation statements)

References 35 publications

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“…Gallo and Block (1991) observed increased P4 secretion during estrous cycles and pregnancy when rbGH was injected and speculated that these effects may have been caused by an increase in IGF-I production stimulated by the rbGH treatment (Spicer et al 1990). However, the length and regularity of estrous cycles were not affected by rbGH treatment in the study by Gallo and Block (1991) (Sirinathsinghji et al 1983). No data are available which demonstrate effects of rbGH or milk yield on p-endorphin production and all of the above listed possibilities require investigation.…”

Section: Effects Of Growth Hormone On Body Conditionmentioning

confidence: 70%

A review of bovine growth hormone

Burton¹,

McBride²,

Block³

et al. 1994

Can. J. Anim. Sci.

132

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. 74: 16'7-201. Unprecedented numbers of technical papers, abstracts, and short communications have been published in the past decade regarding the effects of exogenous bovine growth hormone on milk production, health, and reproductive efficiency of treated dairy cows. In well-managed dairy herds, exogenous growth hormone increases milk production without altering normal variability in milk composition. This has held true regardless of dairy breed tested, geographical location studied, or feeding management system used. Also consistent across studies is the rapidity of the galactopoietic effect of administered bovine growth hormone, which arises from altered partitioning and use of post-absorptive nutrients and increased synthetic capacity of the mammary gland. Growth hormone and its associated peptide, insulin-like growth factor-I, are now known to provide chronic lipolytic, diabetogenic, and gluconeogenic signals to target tissues culminating in increased mammary gland availability of glucose and nonesterified fatty acids. Together with yet ill-defined effects on mammary secretory tissue, this homeorhetic control of metabolism elicited by exogenous growth hormone is so efficient that treated cows are not more susceptible to metabolic disorders than untreated cows. However, some studies have reported an increased frequency of mastitis in groups of treated cows. This has been attributed mainly to increased milk volume in the mammary glands of treated cows and no convincing data are available that show decreased mammary gland immunity as a result of growth hormone treatments. On the contrary, an expanding body of evidence implicates growth hormone as a key neuroendocrine factor that is required for immunological competence. Trends of decreased reproductive efficiency in cows treated with growth hormone have also been reported, but available data imply that this is probably an indirect effect via prolonged negative energy balance in cows treated in early lactation rather than a direct negative effect on estrous cycling via altered reproductive hormone profiles. The objectives of the present review are to bring into focus and summarize pertinent biological discoveries regarding the treatment of dairy cows with recombinant bovine growth hormone, and to explore areas where additional growth hormone research is needed or warranted.Key words: Growth hormone, somatotropin, dairy cows, insulin-like growth factor-I Burton, J. L., McBride, B. W., Block, E., Glimm, D. et Kennelly,E. 1994. L'horrnone de croissance bovinemais au point bibliographique. Can. J. Anim. Sci. 74: . D'innombrables m6moires techniques, r6sum6s analytiques et communications brdves ont 6t6 publi6s dans la dernidre d6cennie au sujet des effets de I'hormone de croissance bovine exogdne sur la production laitidre, sur la sant6 et sur les fonctions de reproduction des vaches laitidres trait6es. Dans les 6levages laitiers bien conduits, la GH exogbne accroit la production de lait sans modifier la variabilit6 normale de sa composition, et cela inddpendamme...

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Section: Effects Of Growth Hormone On Body Conditionmentioning

confidence: 70%

A review of bovine growth hormone

Burton¹,

McBride²,

Block³

et al. 1994

Can. J. Anim. Sci.

132

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“…These studies clearly indicate that EOPs can regulate reproductive function by inhibiting the secretion of GnRH at the level of the central nervous system (CNS) (26,28,34) (Figure 2). …”

Section: Hormonal Control Of Reproductive Function By the Opioid Systemmentioning

confidence: 99%

“…The main function of FSH is to stimulate the proliferation of Sertoli cells during puberty, whereas LH regulates the synthesis of testosterone in the adult testes (24). Administration of morphine is associated with a suppression of LH release, whereas opioid antagonists such as naloxone and naltrexone produce increased serum levels of LH in humans and many animal species (25,26). The opioid-induced inhibition of LH release is mediated by a hypothalamic action because, on the one hand, opioid receptors have been described in purified gonadotrophs and, on the other hand, in vivo treatment with GnRH antagonists completely blocked the release of GnRH induced by naloxone (27)(28)(29).…”

Section: Hormonal Control Of Reproductive Function By the Opioid Systemmentioning

confidence: 99%

Regulation of Male Fertility by the Opioid System

Subirán

Casis

Irazusta

2011

Mol Med

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“…Central injections of either NPY or ␤-END inhibit reproductive behavior in rats and hamsters when primed with estradiol and progesterone (Sirinathsinghji et al, 1983;Wiesner and Moss, 1984;Clark et al, 1985;Gorzalka et al, 1997;Torii et al, 1999;Corp et al, 2001). Furthermore, infusion of ␤-END into the MPN inhibited lordosis (Sirinathsinghji, 1986), suggesting that ␤-END is an endogenous ligand of the -opioid receptor (MOR) in this nucleus.…”

Section: Introductionmentioning

confidence: 99%