Cytophysiological response of the pineal gland to long-term administration of norethisterone (a progestogen-only contraceptive) in rats

Chronic administration of norethisterone for 75 days caused a marked inhibition of the pineal gland activity of cycling albino rats. In addition to a decrease in the nuclear diameter, possibly the cell size also decreased. The progestin, however, failed to induce mitosis in this gland. It is suggested that prolonged administration of norethisterone exerts untoward effects on the pineal gland function in adult female albino rats.

Studies on dimensional characteristics of spermatozoa in pure and strain crosses of White Leghorn cockerels

Sperm head dimensional characteristics were evaluated in three pure strains (M, N, and P) and three strain crosses (N x P, M x N, and P x M) of White Leghorn cockerels. A total of 120 collections from 24 cockerels were taken. The average sperm head length recorded was 14.58 +/- .09 mu, with an average maximum value of 15.29 +/- .19 mu for spermatozoa from the P x M strain cockerels. The average sperm breadth was found to be .722 +/- .005 mu. Maximum values were found for spermatozoa from the M x N strain cockerels that averaged .735 +/- .004 mu. There was a significant difference (P less than .01) between strains for sperm head length. The P x M strain had a significantly longer sperm head length than the other strains. This may be associated with heterosis. There were no significant differences among strains for sperm head breadth. The mean sperm head area was recorded to be 10.61 +/- .08 mu 2. Maximum sperm head area was observed in semen from P x M strain cockerels (11.03 +/- .15 mu 2). The average sperm head shape was found to be 20.14 +/- .22. There were significant differences (P less than .01) among strains for sperm head area and sperm head shape. The repeatability estimates for all the dimensional characteristics showed that they are highly repeatable traits, indicating that additive gene action is playing an important role in the expression of these traits.

The chemistry of pyrrolic compounds. LII. The preferred pathway of electron delocalization in metalloporphyrins

Measurement of the proton coupling constant in the allylic unit, CH3-C=C-H, of the zinc(II), nickel(II) and magnesium(II) chelates of the deuteroporphyrin isomer (3a) points in each case to the double bond of this system having a significantly diminished bond order. Similar data have been obtained for the dication derivative of (3a). These findings are in accord with the view that the π-electron delocalization pathway in porphyrin dications and metalloporphyrins involves the periphery of the molecule as was previously shown for the metal-free porphyrin. New synthetic approaches to the porphyrin (3a) have been studied.

Prolactin induced mitotic activity in the anterior pituitary gland of the chick

The current investigation was undertaken to study whether mammalian prolactin can induce mitotic activity in the anterior pituitary gland in chicks. It was found that intramuscular injections of ovine prolactin (1.5 i.u. and 10 i.u. each daily per bird for 10 days) significantly increased mitotic frequency in the adenohypophysis of juvenile cockerels. It is suggested that ovine prolactin has a mitogenic action on the adenohypophysis of the male chicks and that the reaction may be dose-dependent.

The mitogenic action of prolactin on some endocrine organs of chicks

The aim of the present investigation was to explore the mitogenic action of ovine and bovine prolactin hormones in the thyroid, the parathyroid and the thymus glands of chicks. Both the hormones in lowest dosage (1.5 i.u.) increased the mitotic rate in majority of these organs, but it failed to accelerate the mitotic incidence further or were almost ineffective with the higher dosages (5 i.u. and 10 i.u.). Ovine prolactin showed a higher mitogenic response than that seen with the bovine hormone. It is suggested that prolactin in optimal dosage promotes mitosis in these organs of chicks.

An improved approach for performance evaluation in lower extremity involvement

An investigation has been carried out to confirm the relationship between heart rate and energy expenditure in case of normal and lower extremity handicapped persons and, to explore the difference, if any, between both the relationships. Studies have been made on 8 below-knee amputees fitted with patellar-tendon-bearing (PTB) prostheses and 10 normal subjects, taken as two separate groups and also, on 1 below-knee amputee and 1 control subject as individuals. It has been found that a significant difference exists between both the relationships and hence, separate heart rate-energy expenditure relationship is needed to evaluate the performance of lower extremity handicapped in clinics and in industry without going into the cumbersome, clumsy and time consuming methods of estimating physiological cost.

The influence of testosterone on brain cholesterol

Male sex hormone testosterone propionate induces esterification of brain cholesterol. Esterified cholesterol is absent in the brain of female rats, treatment with male hormone induces esterification. In castrated male rats the esterified cholesterol from brain disappears, whereas supplementation to those animals with testosterone helps in the re-appearance of esterified cholesterol.