Cyclic changes in the pituitary gland of Glyptothorax pectinopterus (McClelland) in correlation with its reproductive cycle

1969 ◽  
Vol 72 (1) ◽  
pp. 148-157 ◽  
Author(s):  
S.S. Khanna ◽  
M.C. Pant
Keyword(s):  
Pituitary Gland ◽  
Reproductive Cycle ◽  
Cyclic Changes

Female reproductive cycle of the water frog Rana epeirotica in northwestern Greece

2002 ◽  
Vol 23 (3) ◽  
pp. 269-280 ◽  
Author(s):  
◽  
Keyword(s):  
Clutch Size ◽  
Reproductive Cycle ◽  
Fat Body ◽  
Reproductive Period ◽  
Continuous Change ◽  
Weight Changes ◽  
Water Frog ◽  
Young Females ◽  
Cyclic Changes ◽  
Northwestern Greece

AbstractThe reproductive cycle of female Rana epeirotica in Lake Ioannina, northwestern Greece was studied from 1998 to 1999. Young females reached sexual maturity at a weight of 26.3 g and a length of 67.2 mm. The annual cyclic changes in weight and histological composition of the ovaries showed that R. epeirotica has a single reproductive period each year. Weight changes of the oviducts followed those shown by the ovaries. A continuous change in the percentage and diameter size of the ovarian follicles through the annual cycle was found. Clutch size ranged from 600 to 2900 ova of 1.3 to 1.6 mm egg diameter. Ovarian weight, clutch size and ovum size were positively correlated to body weight. The weights of fat body and liver had a peak in August and November respectively and they both were reduced considerably during hibernation.

scholarly journals The effect of hypophysectomy of the rabbit

1933 ◽  
Vol 114 (786) ◽  
pp. 64-79 ◽  
Keyword(s):  
Pituitary Gland ◽  
Reproductive Cycle ◽  
Experimental Work ◽  
Sexual Maturity ◽  
Anterior Lobe ◽  
Substitution Therapy ◽  
Adequate Test ◽  
Hormone Assay

In recent years the effect of surgically removing the pituitary gland has received considerable attention. two classes of vertebrates, Amphibia and Mammalia, have largely been used in these studies. Practically all the experimental work on ablation in mammals has been done on two species, namely, dogs (Cushing et al ., 1910; Aschner, 1912; Houssay, 1931; and many others), and more recently rats (Smith, 1930; and others). Following the epoch-making discovered of Smith and Engle (1926) and Aschheim and Zondek (1927), that implanted pituitary gland will hasten sexual maturity in the rat, a number of workers have been attempting to isolate the hormones from the anterior lobe. It has become increasingly apparent that adequate test animals are necessary for the physiological assay of the various hormone fractions and it is now equally apparent that only with animals whose pituitaries have been removed may purified products be assayed with any certainty. The peculiarities of the rabbits reproductive cycle and also its possible utility for hormone assay, make it unusually interesting for studies on the effect of hypophysectomy, but the inaccessibility of the gland has somewhat retarded work on this species. In conjunction with Dr. L. L. Smith, however, method for ablating the pituitary was recently elaborated (Smith and White, 1931) which left the animals essentially healthy so that they survived for considerable periods. It therefore seemed interesting to determine the extent of the changes caused by hypophysectomy in the rabbit and to attempt substitution therapy with purified hormones. The data on untreated hypophysectomized animals will be presented in the present paper.

The Cyclic Changes in the Pituitary Gland and Gonads of Siganus rivulatus from the Red Sea (Hurghada Area)

1996 ◽  
Vol 7 (1) ◽  
pp. 271-284
Author(s):  
M. ZAKI ◽  
A. MASSOUD ◽  
G. MADKOUR ◽  
N. EL-FIKY ◽  
J. EL-MESIRY
Keyword(s):  
Pituitary Gland ◽  
Red Sea ◽  
Siganus Rivulatus ◽  
Cyclic Changes

scholarly journals Cyclic Changes In The Hypothalamo Neurohypophysial System of Xenentodon Cancila (HAM.)

2013 ◽  
Vol 1 (02) ◽  
pp. 12-19
Author(s):  
Z. B. Khuroo
Keyword(s):  
Pituitary Gland ◽  
Close Association ◽  
Third Ventricle ◽  
Neurosecretory System ◽  
Pars Intermedia ◽  
Intermediate Lobe ◽  
Optic Chiasma ◽  
Hypothalamic Nuclei ◽  
Xenentodon Cancila ◽  
Cyclic Changes

The presence of functional hypothalamo-hypophysial neurosecretory system in vertebrates has led to revise earlier views regarding the hypothalamus-pituitary relationship. The hypothalamo-neurohypophysial system which consists of hypothalamic nuclei, their axonal fibres forming tractus preoptico-hypophyses and the neurohypophysis) works as a morphological as well as a physiological connection between the hypothalamus and the pituitary gland. In fishes, fibres from the neurosecretory hypothalamic nuclei terminate in the neurohypophysis, which remains inter digitized with the adenohypophysis and provides a very close association between the neurosecretory fibres and pars intermedia of the pituitary gland forming a neuro-intermediate lobe. Hypothalamo-Neurosecretory complex of Xenentodon cancila consists of Nucleus Pre-opticus (NPO), Nucleus Lateralis Tuberis (NLT) and their axonal tracts. NPO is a paired structure situated on either side of the third ventricle anterodorsal to the optic chiasma. NPO is divisible into a dorsal Pars Magnocellularis (PMC) consisting of large neurosecretory cells and Pars Parvocellularis (PPC) formed of smaller neurons. Neurons of PMC and PPC contribute beaded axons to form neurohypophysial tract. Herring bodies are seen in the anterior as well as posterior neurohypophysis.

scholarly journals The reproductive processes of certain mammals. III.—The reproductive cycle of the male ferret

1932 ◽  
Vol 110 (767) ◽  
pp. 295-312 ◽  
Keyword(s):  
Breeding Season ◽  
Reproductive Cycle ◽  
Reproductive Tract ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Interstitial Tissue ◽  
Quiescent Period ◽  
Cyclic Changes ◽  
Reproductive Processes ◽  
Periodic Changes

Cyclic changes in the reproductive organs of male mammals have been studied in a few forms only, but the information available reveals interesting differences in the duration of reproductive activity, and in the correlation between the various organs. Marshall (1911) has described the reproductive cycle in the male hedgehog. Regaud (1904), Tandler and Grosz (1911) and Lecaillon (1909) have studied the mole, but with conflicting results. Rasmussen (1917 and 1918) gives detailed information of the periodic changes in the interstitial tissue of the testis in the woodchuck, and more recently Courrier (1923) has investigated the reproductive cycle in various bats, in the mole, hedgehog, and marmot. The work of Marshall (1904), Robinson (1918) and Hammond and Marshall (1930) has established that in the female ferret the breeding season is restricted and lasts from April to August ; during the remaining months of the year the reproductive organs are in a state of quiescent anœstrus. The first mating occurs in March or April. The present investigation was undertaken in order to determine the duration of the quiescent period in the male ferret and to compare the changes in the testis tubules with those in the interstitial tissue and accessory organs. The condition of the reproductive tract has accordingly been studied at various times of the year, and an attempt has been made to assess the changes in the organs and in their constituent parts.

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