PMID- 15816408
OWN - NLM
STAT- MEDLINE
DCOM- 20050512
LR  - 20131121
IS  - 0019-5189 (Print)
IS  - 0019-5189 (Linking)
VI  - 43
IP  - 3
DP  - 2005 Mar
TI  - Seasonal effects of melatonin on ovary and plasma gonadotropin and vitellogenin 
      levels in intact and pinealectomized catfish, Clarias batrachus (Linn).
PG  - 224-32
AB  - Effects of daily administration of melatonin for 15 days were evaluated with 
      respect to ovarian activities and plasma gonadotropin (GtH II) and vitellogenin 
      (Vg) levels in intact (INT) and pinealectomized (Px) female catfish, C. 
      batrachus, during preparatory (April), prespawning (May and June), spawning 
      (July) and post-spawning (September) periods. Px (saline control groups) caused a 
      stimulatory effect during preparatory (with respect to Vg synthesis and 
      incorporation) and prespawning (with respect to Vg synthesis) periods whereas no 
      effect was observed during spawning and post-spawning periods with respect to the 
      reproductive parameters studied. During April, melatonin-treatment significantly 
      decreased plasma GtH II levels and percentage of vitellogenic oocytes without any 
      significant changes in plasma Vg levels and gonadosomatic index (GSI). During 
      early prespawning period, in May, 50microg melatonin brought about a significant 
      reduction in plasma GtH II levels in INT group, whereas 100microg caused a 
      decrease in all parameters; on the other hand, in Px groups both dose levels 
      proved to be inhibitory. In June (late prespawning period) melatonin-treatment 
      could not bring about any change in GSI and plasma Vg levels compared to the 
      control groups regardless of Px but plasma GtH II and mean number of yolky 
      oocytes were significantly reduced in melatonin-treated INT group. During 
      spawning period (July) melatonin inhibited the GSI, mean number of yolky oocytes 
      and plasma GtH II levels without affecting plasma Vg levels. In September 
      (post-spawning period), melatonin did inhibit both GSI and plasma GtH II levels. 
      The results, thus, indicate that melatonin showed variable effects (inhibitory 
      and/or no effect) to GSI, mean number of yolky oocytes and plasma Vg levels but a 
      consistent inhibiton of plasma GtH II levels indicating that melatonin may 
      control the reproduction by blocking the GtH II release from the pituitary via 
      affecting the hypothalamo-hypophysial axis.
FAU - Ghosh, Juthika
AU  - Ghosh J
AD  - Department of Zoology, Visva Bharati University, Santiniketan 731 235, India.
FAU - Nath, Panchanan
AU  - Nath P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - India
TA  - Indian J Exp Biol
JT  - Indian journal of experimental biology
JID - 0233411
RN  - 0 (Gonadotropins)
RN  - 0 (Vitellogenins)
RN  - JL5DK93RCL (Melatonin)
SB  - IM
MH  - Animals
MH  - Catfishes
MH  - Enzyme-Linked Immunosorbent Assay
MH  - Female
MH  - Gonadotropins/*blood/*metabolism
MH  - Hypothalamo-Hypophyseal System/physiology
MH  - Melatonin/*pharmacology
MH  - Organ Size
MH  - Ovary/*drug effects/physiology
MH  - Pineal Gland/*physiology
MH  - Reproduction
MH  - Seasons
MH  - Temperature
MH  - Time Factors
MH  - Vitellogenins/*blood/*metabolism
EDAT- 2005/04/09 09:00
MHDA- 2005/05/13 09:00
CRDT- 2005/04/09 09:00
PHST- 2005/04/09 09:00 [pubmed]
PHST- 2005/05/13 09:00 [medline]
PHST- 2005/04/09 09:00 [entrez]
PST - ppublish
SO  - Indian J Exp Biol. 2005 Mar;43(3):224-32.