Browsing by Author "C.J. Dominic"

Now showing 1 - 20 of 85

Anterior and posterior groups of portal vessels in the avian pituitary
(1969) C.J. Dominic; Ram Murat Singh
Distinct anterior and posterior groups of portal vessels originating from the primary capillary plexus of the median eminence and supplying, respectively, the cephalic and caudal lobes of the pars distalis of the avian pituitary have been demonstrated in fifteen species of birds. It is suggested that the existence of two distinct groups of portal vessels is correlated with the cytological differentiation of the pars distalis and may be widespread among birds. © 1969.
Anterior and posterior groups of portal vessels in the avian pituitary: incidence in forty nine species
(1975) K.B. Singh; C.J. Dominic
The hypophyseal portal vessels were studied in forty nine species of birds. The primary capillary plexus in the median eminence is single or divided into an anterior and a posterior plexus. Irrespective of whether the primary capillary plexus is single or divided, distinct, non interconnected anterior and posterior groups of portal vessels are present in all the species investigated. The anterior group of portal vessels originates in the anterior region of the median eminence and breaks up into capillaries in the cephalic lobe of the pars distalis; the posterior group of portal vessels originates in the posterior region of the median eminence and breaks up into capillaries in the caudal lobe of the pars distalis. This type of regional distribution of portal vessels appears to be of general occurrence in the avian pituitary. The median eminence in the species investigated shows an AF positive anterior region and an AF negative posterior region. The pars distalis is differentiated into histologically distinct cephalic and caudal lobes. The arrangement of the portal vessels into anterior and posterior groups provides morphological basis for the view that the functions of the cephalic lobe may be controlled by the anterior median eminence, whereas those of the caudal lobe may be controlled by the posterior median eminence. However, experimental data available to date do not suggest a physiological significance to the widespread incidence of the regional distribution of portal vessels in the avian pituitary.
Bromocriptine-induced implantation failure in mice: Failure of the stud male to protect pregnancy
(1992) G. Archunan; C.J. Dominic
[No abstract available]
Changes in the hypothalamic neurosecretory system of the musk shrew, Suncus murinus L. during pregnancy and lactation
(1975) A. Kulshreshtha; C.J. Dominic
[No abstract available]
Changes induced by formalin in the hypothalamic neurosecretory system of the spotted owlet, athene hrama temminck
(1975) Kunwar Bahadur Singh; C.J. Dominic
Histological changes induced in the HNS of the spotted owlet, Athene hrama Temminck. by injection of 1 ml 5 or 10% formalin arc described. No difference could be detected in the response of the HNS to 5 or 10% formalin administration. In the HNS of birds killed within 5 tnin of formalin administration, there was only partial depletion of NSM from the neurons, the tract and the NL: The quantity of NSM in the AME remained more or less unchanged. In animals killed 10-90 min after formalin injection, the depletion of NSM from the neurons, the tract and the NI, was more complete. The neurons of the preoptic division of the SON exhibited the maximum response: These neurons were also moderately hypertrophied. The NL also was hypertrophied in some animals; the NSM in the AME registered only a partial loss. The interval between formalin administration and killing did not influence the degree of changes in the HNS. The depletion of NSM was no greater at 90 min following formalin injection than at 10 min. Since it is well established that formalin stress causes augmented secretion of ADII and that there is a close functional relationship existing between ADH and NSM. the depletion of NSM noticed in the HNS of the spotted owlet following formalin administration is interpreted as indicating augmented secretion of ADH. Hence it seems that the responses of the HNS of birds to formalin stress are comparable to those of the 1INS of mammals. The results thus provide histological evidence in favour of the concept that stressful stimuli cause increased secretion of ADH. © 1975 S. Karger AG, Basel.
Changes induced by morphine administration in the hypothalmic neurosecretory system of the spotted owlet, Athene brama Temminck
(1975) K.B. Singh; C.J. Dominic
[No abstract available]
Chlorpromazine Inhibition of Dehydration-Induced Histological Changes in the Hypothalamic Neurosecretory System of the Musk Shrew, Suncus Murinus L
(1971) Aruna Kulshreshtha; C.J. Dominic
The effect of chlorpromazine (CPZ) on the histology of the hypothalamic neurosecretory system (HNS) was investigated in Suneus murinus L. which were injected with hypertonic saline. Chronic saline treatment brought about characteristic histological changes in the neurons of the paraventricular nucleus (PVN) and depletion of neurosecretory material (NSM) from the cytoplasm, stalk median eminence (SME) and the neural lobe (NL). Acute saline treatment affected the neurons of both the PVN and the supraoptic nucleus (SON); there was no detectable depletion of NSM from SME and NL. Pretreatment with or simultaneous administration of CPZ prevented the appearance of the histological changes in the HNS that normally follow chronic and acute treatments with hypertonic saline. Since the hypertonic saline-induced histological changes in the HNS are regarded as morphological manifestations of increased secretion of the antidiuretic hormone (ADH), the inhibition, by CPZ, of these changes is interpreted as providing histological evidence in favour of the diuretic effect of the drug. © 1971, The Japan Endocrine Society. All rights reserved.
Chlorpromazine inhibition of the pheromonal block to pregnancy (the Bruce effect) in mice
(1980) S.C. Sahu; C.J. Dominic
[No abstract available]
Differential rates of fetal growth in two successive pregnancies in the emballonurid bat, Taphozous longimanus hardwicke
(1982) A. Krishna; C.J. Dominic
[No abstract available]
Disposition of the portal vessels of the avian pituitary in relation to the median eminence and the pars distalis
(Birkhäuser-Verlag, 1970) Ram Murat Singh; C.J. Dominic
[No abstract available]
Effect of 1-(2, 4-Dichlorobenzyl)-1H-Indazole-3-Carboxylic Acid (DICA) on the Sex Organs of the Male Laboratory Mouse
(1984) S.K. Singh; C.J. Dominic
Oral administration (50 mg/kg body weight/day, for 28 days) of 1-(2,4-dichlorobenzyl)-1H-indazole-3-carboxylic acid (DICA) induced significant reduction in testicular weight with suppression of spermatogenesis. The seminiferous tubules were devoid of spermatozoa and contained only Sertoli cells, spermatogonia, spermatocytes and several multinucleated giant cells. The Leydig cells, however, remained unaffected in treated animals. The drug also induced significant decrease in the levels of testicular UNA and protein; DNA level, however, remained unaltered. Epididymis in DICA-treated mice presented normal histology except that the lumen contained sperm debris; cauda epididymidal spermatozoa were immotile and often fragmented. DICA treatment caused no change in the level of fructose in the seminal vesicle. DICA-induced alterations were reversible and within 56 days of drug withdrawal the reproductive organs returned to their normal state. © 1984, J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart, New York. All rights reserved.
Effect of 1-p-Chlorobenzyl-1H-Indazol-3-Carboxylic Acid (AF 1312/TS) on the Sex Organs of the Male Laboratory Mouse
(1985) S.K. Singh; C.J. Dominic
[No abstract available]
Effect of acute fracture on the hypothalamic neurosecretory system of the musk shrew, Suncus Murinus L.
(1976) A. Kulshreshtha; C.J. Dominic
[No abstract available]
Effect of alpha-chlorohydrin on the epididymis of the Indian palm squirrel (Funambulus pennanti)
(1986) A. Agarwal; C.J. Dominic
The effects of α-chlorohydrin administration on the epididymis of the Indian palm squirrel were investigated. The drug induced dose- and duration related regressive histological changes in the three epididymal segments. In spite of the regressive changes in the epididymis, spermatogenesis continued uninterruptedly in α-chlorohydrin-treated animals. Treatment with the drug also induced alterations in the levels of epididymal nucleic acids, protein, sialic acid and glycogen. The alterations in the histology and chemical constituents of the epididymis in drug treated animals were completely reversible. Within 21 days after drug withdrawal, epididymal histology and constituents returned to the pre-treatment state.
Effect of bilateral transection of the lateral olfactory tract on the male-induced implantation failure (the Bruce effect) in mice
(1986) G. Rajendren; C.J. Dominic
Bilateral transection of the lateral olfactory tract (LOT) at the rostral level induced anosmia in female mice; by contrast, sectioning of the LOT at more caudal levels failed to induced anosmia in females. Transection of the LOT at all the levels inhibited the alien male-induced implantation failure in newly inseminated mice (the Bruce effect). Sham-operated as well as intact females exhibited a high rate of implantation failure following alien male exposure. The results suggest that the inhibition of the Bruce effect in LOT-transected females is not due to anosmia induced by the operation procedure, but due to interruption of the primary olfactory bulb projections to the posterior parts of the olfactory cortex. Our results rule out the involvement of the nervus terminalis in the Bruce effect. The present report lends support to the involvement of the accessory olfactory system in the transmission of the pheromonal stimulus involved in the male-induced implantation failure. © 1986.
Effect of cyproterone acetate on the epididymis of the Indian palm squirrel, Funambulus pennanti Wroughton
(1984) A. Agarwal; C.J. Dominic
[No abstract available]
Effect of cyproterone acetate on the pregnancy-blocking ability of male mice and the possible chemical nature of the pheromone
(1988) G. Rajendren; C.J. Dominic
Even though castration abolished the ability of alien males to induce implantation failure (the Bruce effect) in newly inseminated females, treatment of intact alien males with the steroidal antiandrogen, cyproterone acetate, for 14 days (short term) did not significantly depress their ability to induce the Bruce effect. However, prolonged treatment (42 days) with cyproterone acetate suppressed the pregnancy-blocking ability of alien males to some extent, possibly due to the antigonadotrophic properties of the drug. Ovariectomized alien females treated with implants of testosterone (androgenized females) exhibited the ability to block implantation in newly inseminated females, but concurrent treatment of androgenized females with cyproterone acetate did not depress this ability. The results strongly suggest that the pheromone involved in the male-induced implantation failure is not the product of an androgen-dependent tissue, but is likely to be a product of androgen metabolism.
Effect of cyproterone acetate on the production of the estrus-inducing pheromone in the wild mouse
(1978) S.D. Pandey; C.J. Dominic
[No abstract available]
Effect of DL-6-(N-α-pipecolinomethyl)-5-hydroxyindane maleate (PMHI) on the testis of the musk shrew Suncus murinus L.
(1979) S. Kumar Singh; C.J. Dominic
[No abstract available]
Effect of ectopic pituitary grafts on the olfactory block to pregnancy in mice [28]
(1967) C.J. Dominic
[No abstract available]