Record Details
The effects of exogenous melatonin on the plasma levels of interstitial cell stimulating hormone in sheep
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The effects of exogenous melatonin on the plasma levels of interstitial cell stimulating hormone in sheep |
| Names |
French, Larry Robert
(creator) Wu, Arthur S. H. (advisor) |
| Date Issued | 1970-05-01 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | There is an increasing body of evidence that the pineal gland acts as a neuroendocrine transducer, translating neural information about environmental lighting condition into hormonal information. In the rat, light controls the production of melatonin which acts via the hypothalamic-hypophyseal pathway to control the function of the gonads, A similar mechanism seems to operate in other laboratory animals. The effect of photoperiod on the onset of the breeding season in large animals such as sheep has been studied, but the mechanism by which light affects their reproduction has not been elucidated. To test the hypothesis that the mechanism by which light controls reproduction in sheep is similar to the mechanism that operates in rats, an experiment was conducted to determine the effects of melatonin on reproductive phenomena in sheep. A solid-phase radioimmunoassay was developed as a means of studying the effects of melatonin on serum interstitial cell stimulating hormone (ICSH). Twenty-eight ewe, ram and wether lambs were divided into a control and a treatment group. Treatment consisted of daily sub-cutaneous injections of 0.1 mg. melatonin per kilogram of body weight administered in propylene glycol. Treatment was initiated on the third day after birth and continued until autopsy just before the suspected onset of puberty. Melatonin in the doses employed caused a significant increase (P < .05) in ovarian weight in ewe lambs and a depression (P < .10) in castration-hypersecretion of ICSH in wether lambs. No other significant effects were observed. The role of melatonin in controlling reproductive phenomena in sheep is still not clear. The known effects of melatonin in rats could not be duplicated in sheep. It appears that the mechanism by which light controls reproduction in sheep is not similar to that which operates in rats. The solid phase radioimmunoassay developed for this experiment proved to be a rapid, sensitive and highly reliable technique for the determination of serum ICSH. |
| Genre | Thesis/Dissertation |
| Topic | Reproduction -- Research |
| Identifier | http://hdl.handle.net/1957/46298 |
