Structure of a pineal gland-derived antigonadotropic decapeptide.

An antigonadotropic decapeptide was extracted from bovine pineal glands, purified by ultrafiltration and Sephadex G-25 gel-filtration chromatography and isolated by serial semi-preparative high performance liquid chromatography. Its primary structure was determined by automated amino acid and microsequence analyses. A synthetic analog of the decapeptide, prepared by solid state methods, was observed to reduce circulating levels of luteinizing hormone and prolactin after intra-atrial injection in male rats.

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland.

The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.

Identification of luteinizing hormone-like proteins in the ovine pineal gland.

A chemical analysis was instigated to investigate the identity of the luteinizing hormone (LH)-like immunoactivity present in ovine pineal protein homogenates. Isolation of pineal LH-like material was accomplished using a 0.1 M ammonium sulphate (pH 4.

Antitumor activity of the pineal gland: effect of unidentified substances versus the effect of melatonin.

There is growing evidence that the pineal gland has antineoplastic properties which, however, can only partially be attributed to its hormone melatonin. While the in vivo tumor-inhibiting activity of melatonin is established, observations on its in vitro effects have been contradictory. The effect of this substance was investigated on six human cancer cell lines and compared to the activity of a partially purified, melatonin-free low molecular weight pineal extract (UMO5R).

Isolation and structure elucidation of bovine pineal arginine vasopressin: arginine vasotocin not identified.

A large number of reports have demonstrated the presence of neurohypophysial hormone-like peptides in mammalian pineal glands and an antigonadotropic function has been ascribed to pineal arginine vasotocin (AVT). We have undertaken large scale purification of bovine pineal neurohypophysial hormone-like substances which demonstrate mouse mammary milk-ejection activity (ME-activity) in vitro. Peptides with ME-activity were extracted from more than 5 kg of bovine pineal glands.