We demonstrated the production and release of a peptide structurally identical with porcine and bovine VIP-28 in human neuroblastoma NB-OK-1 cell line. In the cells, VIP-like immunoreactive (IR-VIP) components of 8 K dalton (Kd), 11 Kd, 18 Kd and 30 Kd were also detected and the 8 Kd and 18 Kd components were apparently released into the culture medium, indicating the possibility of less extended or limited processing of the VIP precursor in the cultured cells of tumor origin. The cells were also shown to produce, simultaneously with the VIP-28, a PHI/PHM-like immunoreactive (IR-PHI/PHM) component which coeluted with synthetic PHM-27, not PHI-27, in reverse-phase high performance liquid chromatography (HPLC). In addition to the PHM-27-like component, another IR-PHI/PHM component was detected in the cell extract which eluted in HPLC immediately before synthetic PHM-27 and crossreacted with PHI-27 amino-terminal specific antiserum but not with PHI-27 central-portion specific or PHM-27 carboxyl-terminal specific antiserum. The presence in NB-OK-1 cells of this IR-PHI/PHM component related to the amino-terminal portion of PHI/PHM suggested possible alternative(s) of post-translational processing of the VIP precursor in the cells in terms of the production of PHM-27-related peptides.

Amino Acid Sequence↗

PubMedDate not supplied

Uteroplacental circulatory disturbance mediated by prostaglandin f2alpha in rats exposed to microwaves. hiro-n@po.incl.ne.jp.

To clarify the effects of microwaves on pregnancy, uterine or uteroplacental blood flow and endocrine and biochemical mediators, including corticosterone, estradiol, prostaglandin E(2) (PGE(2)), and prostaglandin F(2)alpha (PGF(2)alpha), were measured in rats exposed to continuous-wave (CW) microwave at 2 mW/cm(2) incident power density at 2450 MHz for 90 min. Colonic temperature in virgin and pregnant rats was not significantly altered by microwave treatment. Microwaves decreased uteroplacental blood flow and increased progesterone and PGF(2)alpha in pregnant, but not in virgin rats. Intraperitoneal (i.p.) administration of angiotensin II, a uteroplacental vasodilator, before microwave exposure prevented the reduction in uteroplacental blood flow and the increased progesterone and PGF(2)alpha in pregnant rats. Increased corticosterone and decreased estradiol during microwave exposure were observed independent of pregnancy and pretreatment with angiotensin II. These results suggest that microwaves (CW, 2 mW/cm(2), 2450 MHz) produce uteroplacental circulatory disturbances and ovarian and placental dysfunction during pregnancy, probably through nonthermal actions. The uteroplacental disturbances appear to be due to actions of PGF(2)alpha and may pose some risk for pregnancy.

Angiotensin II↗