Non-fertilizing spermatozoa: initiators of gestational physiology.

It is suggested that spermatozoa may have reproductive functions in the human female beyond participation in the process of fertilization, that there may be sperm-related infertilities associated with these "other" functions of spermatozoa and that if they exist the "other"-function centered infertilities ought to be susceptible to treatment.

Reproduction in mice: protein kinase mimics the sperm effect on preimplantation embryo development.

The creation of an environment in mouse fallopian tubes that is sufficient to sustain preimplantation embryo development is known to require the participation of spermatozoa in excess of those involved in the process of fertilization. We have now found that highly purified cAMP-dependent protein kinase can substitute for spermatozoa in the facilitation of the first cleavage of mouse embryos. Both spermatozoa and purified protein kinase induce increases in fallopian phosphoproteins.

Seasonal variation in estrous cycling in the mouse: implications for artificial insemination.

Artificial insemination in the C3HeB/FeJ inbred strain of mice has been shown to be more successful at the middle and end of the calendar year. The reasons are twofold: 1) an increase in the number of normal estrous cycles exhibited by females and 2) an increase in the tightness of the phasing of ovarian and vaginal events. The latter phenomenon was found to be the key to the success of artificial insemination, since it permitted the use of vaginal smears to predict accurately the time females could be expected to ovulate and, therefore, the appropriate time for artificial insemination.

Reproduction in mice: liver enlargement in mice during pregnancy and lactation.

The mechanism of liver enlargement during pregnancy was investigated in the C57BL/6J strain of mice. The C57BL/6J female exhibited a two-fold increase in liver mass during pregnancy. After the completion of lactation the size of the liver was reduced.

New pathway of conversion of pyridoxal to 4-pyridoxic acid.

The only enzyme demonstrated so far to catalyze the formation of 4-pyridoxic acid, the final excretory product of vitamin B6, was aldehyde oxidase. In this paper we have presented an evidence that another enzyme, NAD+-dependent aldehyde dehydrogenase, is capable of catalyzing this reaction. Rat mutants with high, low and no aldehyde oxidase activity excrete the same amount of isotope after a single injection of 3H-pyridoxol in a 12-day experiment; 4-pyridoxic acid is also present in the urine of animals without aldehyde oxidase activity.