The role of some extra-gonadal hormones on the circannual ovarian cycle of the flat head grey mullet, Mugil cephalus L.

作者：Das Puranjan; Pramanick Kousik; Maity A; Maiti B R^*

来源：Biological Rhythm Research, 2013, 44(5): 830-843.

DOI：10.1080/09291016.2013.770291

• pineal
• thyroid
• adrenal
• insulin
• blood glucose
• ovarian cycle
• mullet

The role of extra-gonadal hormones on the induction of circadian ovarian cycle of the grey mullet Mugil cephalus L. was investigated. The findings revealed that thyroid hormones (T-3 and T-4) showed their peak with lowest thyroid stimulating hormone level in pre-spawning, with another peak in April during post-spawning phase. Serum cortisol, epinephrine and norepinephrine concentrations were highest in spawning phase. Insulin level was the highest followed by the lowest blood glucose level in the spawning phase. But, pineal N-acetyl serotonin (NAS) and melatonin (MEL) levels were least with the highest level of serotonin in spawning phase. The findings suggest that (a) T-3 and T-4 are involved probably to trigger oocyte growth and vitellogenesis. (b) Whereas, cortisol, epinephrine, norepinephrine and insulin synergistically help to induce final maturation in the spawning phase. (c) Pineal hormonal profiles (NAS and MEL) were reversely altered to those of spawning, indicating negative role of these hormones especially on oocyte growth, vitellogenesis and oocyte maturation in the mullet. Thus, all the extra-gonadal hormones, except pineal, have a role in regulation of circannual ovarian cycle in the flat head grey mullet.

• 出版日期2013-10-1