Effects of pinealectomy and melatonin injections at different seasons on ovarian activity in the lizardAnolis carolinensis

✍ Scribed by Levey, Irwin L.

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 484 KB
• Volume: 185
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401850205

✦ Synopsis

Abstract

The short‐term effects of pinealectomy and melatonin treatment on ovarian activity in the lizard, Anolis carolinensis were examined at various times of the year. Animals were maintained under short photoperiod (6L:18D) at a constant temperature of 31 ± 1°C.

Destruction of the epiphysis by heat cautery in November and January caused significant follicular development within 14 days. Daily administration of 10 μg synthetic melatonin blocked ovarian stimulation resulting from pinealectomy. Ovarian sensitivity to pinealectomy decreased with the onset of seasonal reproductive activity and was absent at the end of the normal breeding season, i.e., September.

These observations support the hypotheses that, under conditions of short photoperiod and high environmental temperature, (a) the pineal organ can modify ovarian activity in Anolis; (b) there exists a definite seasonal sensitivity to this influence; and (c) melatonin may be an active agent of pineal function.