In the mammalian female reproductive tract, tachykinin neuropeptides, such as substance P (SP), are localized to a population of sensory fibers and their precise physiological role is still unknown. The aim of the present study was to characterize the population of tachykinin receptors in the pregnant rat uterus and to assess their regulation during the course of pregnancy and after delivery. The expression of the tachykinin NK(1) receptor (NK(1)R), the tachykinin NK(2) receptor (NK(2)R), and the tachykinin NK(3) receptor (NK(3)R) in uteri from rats at different stages of pregnancy and on Day 1 postpartum was investigated by using a semiquantitative reverse transcription-polymerase chain reaction. The contractile effect of tachykinin receptor agonists acting selectively on the NK(1)R, the NK(2)R, or the NK(3)R was investigated by conventional organ bath techniques. Serum levels of estrogen and progesterone were measured by RIA. Our data show that the expression and function of NK(1)R and NK(3)R varied along the course of pregnancy and at postpartum. Uterine NK(2)R mRNA levels remain stable during the course of pregnancy and at Day 1 postpartum; and the contractions elicited by activating selectively the NK(2) receptor in the presence of the neutral endopeptidase inhibitor phosphoramidon (1 microM) were similar in early, mid, or late pregnancy. These results show that the expression and function of tachykinin receptors within the uterus vary with reproductive state and length of gestation, supporting a role for tachykinins in pregnancy and/or parturition in the rat.

Examination of the polar components of the green seaweed Caulerpa taxifolia (Vahl) C. Agardh, which is heavily spreading in the northeastern Mediterranean, led to two families of compounds. The new (2R)‐3‐O‐β‐D‐galactopyranosyl‐1‐O‐[(7Z,10Z,13Z)‐hexadeca‐7,10,13‐trienoyl]‐2‐O‐[(9Z,12Z,15Z)‐octadeca‐1,12,15‐trienoyl]‐sn‐glycerol (2) was isolated in low abundance, like the analogues 1 and 3 already known from freshwater cyanobacteria. The acyl positions in 1 – 3 were determined by enzymatic methods and the absolute configuration from the O‐galactosylglycerol obtained upon alcaline methanolysis. More abundant were the (4‐hydroxyphenyl)‐ and (3,4‐dihydroxyphenyl)pyruvic acid methyl esters, occurring in the enol (Z) forms 13a and 14a accompanied by very minor (E) forms 13b and 14b. The latter became predominant on UV irradiation of 13a or 14a, allowing the determination of the C=C configuration of these isolatable, stable enols from 1H,13C NMR couplings (larger H−C(3)/C(1) coupling constant in the (E) than in the (Z) isomer). Contrary to literature implications, the O‐galactosylglycerolipids 1 – 3 lack any cholinergic or histaminergic activity; similarly, enols (= α‐keto esters) 13 and 14 or terpenoids of this seaweed were also devoid of such biological activities (see Table).