Maitra SK

References (2)

Title : Testicular functions and serum titers of LH and testosterone in methyl parathion-fed roseringed parakeets - Maitra_2008_Ecotoxicol.Environ.Saf_71_236
Author(s) : Maitra SK , Mitra A
Ref : Ecotoxicology & Environmental Safety , 71 :236 , 2008
Abstract : Adult male roseringed parakeets were fed concentrations (0, 10 or 20 microg/100g body wt./day) of methyl parathion (MP) for 5 or 10 days. There were four sampling periods for each treatment group. The first two sampling periods were after 5 or 10 days of daily dosing. In two other sampling periods, birds were given daily doses for 10 days, and sampling occurred at 5 or 10 days after the end of treatment. A significant dose- and duration-dependent reduction in the paired testicular weight, seminiferous tubular diameters, the number of tubules with healthy germ cells, plasma acetylcholinesterase (AChE) activity and plasma levels of luteinizing hormone (LH) and testosterone occurred in MP-fed birds. The inhibitory influences of MP persisted till day-5 and followed by recovery from the gonado-suppressive effects of MP at day-10 after the end of last treatment for 10 days. These findings provide the first experimental evidence that MP-induced testicular dysfunctions in parakeets possibly results from an impaired activity of hypophysial-gonadal axis. Moreover, it is evident that the organophosphorous (OP)-induced changes in the avian testes are reversible.
ESTHER : Maitra_2008_Ecotoxicol.Environ.Saf_71_236
PubMedSearch : Maitra_2008_Ecotoxicol.Environ.Saf_71_236
PubMedID: 18029014

Title : Influence of methyl parathion on gametogenic and acetylcholinesterase activity in the testis of whitethroated munia (Lonchura malabarica) - Maitra_1996_Arch.Environ.Contam.Toxicol_30_384
Author(s) : Maitra SK , Sarkar R
Ref : Archives of Environmental Contamination & Toxicology , 30 :384 , 1996
Abstract : Adult male whitethroated munias, Lonchura malabarica (Aves; Passeriformes), were orally administered with methyl parathion (O, O-dimethyl O-(4-nitrophenyl) phosphorothioate), an extensively used organophosphate pesticide, in graded sublethal dose (5 micro g-, or 10 micro g-, or 20 micro g/100 g body wt/day) for variable durations (1-, 5-, or 10 day/s) during their peak reproductive activities in an annual gonadal cycle. No subtle changes in the feeding behavior, mobility, and body weight were noted between the control and different groups of pesticide-fed birds. As a result of the treatment, the paired testicular weight became reduced significantly only after 10 days at 10 micro g and 20 micro g dose levels, but significant decrease in the number of tubules containing healthy germ cells occurred even after single administration of methyl parathion (MP) at the lowest dose (5 micro g/100 g). With the increase in dose and progress of treatment, the number of tubules with healthy germ cells became gradually decreased. The activity of acetylcholinesterase (AChE) in both the brain and testes of MP-treated birds was inhibited in a dose and duration dependent manner. A significant negative correlation was observed between the number of tubules containing degenerated germ cells in the testis and the AChE activity in both the brain and testes of MP-administered birds. However, no remarkable changes in the cytomorphological features, including the nuclear diameter of Leydig cells, were noted in any testis of the pesticide-treated munias. The results of the present investigation suggest that methyl parathion ingestion is harmful to male gametogenic functions in the studied passeriform bird, and the given pesticide may exert its antigonadal effect by impairing cholinergic functions of the brain and/or testes.
ESTHER : Maitra_1996_Arch.Environ.Contam.Toxicol_30_384
PubMedSearch : Maitra_1996_Arch.Environ.Contam.Toxicol_30_384
PubMedID: 885496