Carbofuran induced block of compensatory ovarian growth in hemicastrated albino mice.

Carbofuran, a systemic N-methyl carbamate pesticide was orally administered at doses of 0.4, 0.7, 1 and 1.3 mg/(kg day) to normal hemicastrated (HC) mice for 15 consecutive days to investigate the effects on compensatory ovarian growth. Sham-operated and hemicastrated control mice were administered a similar quantity of olive oil. The vaginal smear and body weight of the mice were recorded daily and mice were sacrificed on day 16. The results revealed that the HC control mice showed 54.58% increase in the ovary weight of the remaining left ovary and many follicles, corpora lutea and showed normal estrous cycle as compared to Sham-operated control mice. The remaining left ovaries of the mice treated with 1.3 mg carbofuran showed 0.82% increase in the ovary weight and significant decrease in the number of developing follicles, corpora lutea, increase in many atretic follicles, the estrous cycle and its phases were affected when compared to HC control mice. In HC mice treated with 1 mg/(kg day) carbofuran resulted in 12.63% increase in the ovary weight and showed significant decrease in follicles, corpora lutea and many increased atretic follicles. The estrous cycle was affected with significant decrease in estrus phase and increase in diestrus phase. In HC mice treated with 0.7 mg/(kg day) carbofuran showed 26.30% increase in ovary weight and showed normal number of follicles and the mice showed normal number of estrous cycles but the estrus and diestrus phases were affected significantly. However, HC mice treated with 0.4 mg/(kg day) carbofuran revealed 33.09% increase in the ovary weight with no significant change in the follicles and estrous cycle as compared with that of HC control mice. There was no significant change in the body weight gain and weight of the organs such as uterus, kidney, adrenals, liver, spleen, thymus and thyroid in all the carbofuran treated mice. These observed effects of carbofuran on ovary, follicles and estrous cycle are considered to be hormonal imbalance.

Temporal effect of carbofuran on estrous cycle compensatory ovarian hypertrophy and follicles in hemiovariectomized albino mice.

Carbofuran, a systemic N-methyl carbamate pesticide was administered orally with an effective dose of 1.3mg/kg per day to hemiovariectomized (HOVX) mice for 5, 10, and 15 days. Sham-operated and HOVX control mice were administered a similar quantity of olive oil. The vaginal smear and body weight of the mice were recorded daily and mice were sacrificed on day 16. The results of the present study indicate that there is a significant decrease in the duration of the estrus with a concomitant significant increase in the duration of the diestrus with carbofuran treatment for 10 days. In the HOVX mice treated with carbofuran for 15 days there was a significant decrease in the length of the estrous cycle and the duration of the estrus and metestrus with a concomitant significant increase in the diestrus. There was a significant increase in the ovarian weight in HOVX control mice when compared to that of the sham operated control mice. HOVX mice treated with carbofuran for 10 and 15 days showed a significant decrease in the relative ovarian weight with a concomitant inhibition of compensatory ovarian hypertrophy in HOVX mice. There was also a significant decrease in the ovarian growth rate in relation to the contralateral ovary of the same animal. There was a significant decrease in the number of small and total number of healthy follicles with a concomitant significant increase in the number of medium, large and total number of atretic follicles in HOVX mice treated with carbofuran for 10 days. There was a significant decrease in the number of small, medium, large, and total number of healthy follicles with a concomitant significant increase in the number of medium, large, and total number of atretic follicles in HOVX mice treated with carbofuran for 15 days. The administration of carbofuran in the present study showed that there is no significant change in the body and organs weight such as uterus, kidney, adrenals, liver, spleen, thymus and thyroid in all the carbofuran-treated mice. The above findings such as disruption in the estrous cycle, inhibition of compensatory ovarian hypertrophy, and follicular toxicity may be due to a direct effect on the ovary or through the hypothalamo-hypophysial-ovarian axis.

Morphometric analysis of follicular growth and biochemical constituents in albino rats exposed to mancozeb.

Mancozeb, an ethylenebisdithiocarbamate (EBDC), was administered orally at a dose of 700 mg/kg body weight/day to female virgin rats for 5, 10, 20, and 30 days to examine the effect on ovarian follicular development. No significant change occurred in the number of estrous cycles and the duration of proestrus, estrus, and metestrus, but mancozeb treatment for 5 days significantly increased the duration of diestrus. Mancozeb treatment for 10 days significantly increased the number of estrous cycle and the duration of estrus, with a concomitant significant increase in diestrus, but no change in proestrus and metestrus. With mancozeb treatment for 20 and 30 days, the number of estrous cycles and duration of proestrus, estrus, and metestrus were significantly decreased, with a concomitant significant increase in the duration of diestrus. Exposure of rats to mancozeb for 5 days resulted in a significant decrease in stage II and the total number of healthy follicles but no change in atretic follicles. Mancozeb treatment for 10 days resulted in a significant decrease in stages I, II, and IV and in the total number of healthy follicles. A significant increase in atretic follicles was found in rats treated with mancozeb for 20 and 30 days. No significant change occurred in body and organ weights in any group, but the thyroid weight of 20 and 30 days mancozeb-treated rats was significantly increased. The level of protein in the ovary was significantly decreased, but no change was found in the uterus and liver of mancozeb-treated animals. The level of glycogen was significantly decreased in the ovary and the uterus with mancozeb treatment, but not in the liver. With mancozeb treatment, the levels of phospholipids and neutral lipids were significantly increased in the liver but significantly decreased in the uterus. The change in the biochemical constituents of ovary, uterus, and liver was duration dependent. The results of the study thus indicate a marked disruption of the estrous cycle, pathological changes in the gonads, and organ-specific biochemical changes in rats after exposure to mancozeb.

Induction of gonadal toxicity to female rats after chronic exposure to mancozeb.

Mancozeb, a fungicide of ethylenebisdithiocarbamate group was orally administered at doses of 500, 600, 700 and 800 mg/kg body weight/day to normal virgin rats of Wistar strain for 30 days. The vaginal smear and body weight of the rats were recorded daily and rats were sacrificed on 31st day. Estrous cycle was effected by showing a significant decrease in the number of estrous cycle, duration of proestrus, estrus and metestrus with concomitant significant increase in the duration of diestrus in all the mancozeb treated groups when compared with controls. There were a significant decrease in the number of healthy follicles and a significant increase in the number of atretic follicles in all the mancozeb treated groups when compared with controls. The histologic observation of the ovary revealed the presence of less number of corpora lutea and the size of the ovary was also reduced in high doses of mancozeb treated rats. There was a significant increase in the thyroid weight in all the mancozeb treated rats except in 500 mg/kg/d. In rats treated with 500 mg/kg/d showed a significant increase in the level of total lipids in the liver. In rats treated with 600 mg/kg/d mancozeb showed a significant decrease in the levels of glycogen and total lipids in the uterus and total lipids in the liver. In rats treated with 700 mg/kg/d showed a significant decrease in the levels of protein in ovary, glycogen, total lipids, phospholipids and neutral lipids in the uterus and a significant increase in the levels of phospholipids, neutral lipids in the ovary and total lipids, phospholipids and neutral lipids in the liver. In rats treated with 800 mg/kg/d showed a significant decrease in the levels of protein and glycogen in the ovary and protein, glycogen, total lipids, phospholipids and neutral lipids in the uterus and a significant increase in the levels of total lipids, phospholipids and neutral lipids in the ovary and liver when compared with controls. These observed effect of mancozeb on the estrous cycle, follicles and biochemical constituents may be due to imbalance in the hormone or toxic effect.