Determination of biogenic diamines with a vaporisation derivatisation approach using solid-phase microextraction gas chromatography-mass spectrometry.

A gas-phase on-fibre derivatisation method for the determination of putrescine and cadaverine by gas chromatography/mass spectrometry using trifluoroacetylacetone (TFAA) has been studied and optimised. Small amounts (2μl) of putrescine, cadaverine and TFAA standards were vaporised at high temperature in a 20cm(3) closed SPME vial. The subsequent derivatives were recovered from the headspace of the vial using a PDMS/DVB fibre.

Optimising cell temperature and dispersion field strength for the screening for putrescine and cadaverine with thermal desorption-gas chromatography-differential mobility spectrometry.

Biogenic amines, and putrescine and cadaverine in particular, have significant importance in the area of food quality monitoring, and are also potentially important markers of infection, for cancer, diabetes, arthritis and cystic fibrosis. A thermal desorption-gas chromatograph-heated differential mobility spectrometer was constructed and the significant effect of interactions between cell temperature and dispersion field strength on the observed responses studied. The experiment design was a Box-Wilson central composite design (CCD) over the levels of 10-24 kVcm(-1) for dispersion field strength and 100-130 degrees C for cell temperature.

Analytical characterisation of the routes by thermolytic decarboxylation from tryptophan to tryptamine using ketone catalysts, resulting in tetrahydro-beta-carboline formation.

N-Alkylated tryptamines have complex psychoactive properties. Routes for clandestine synthesis are described on Internet websites one of which involves the thermolytic decarboxylation of tryptophan to tryptamine as a precursor to psychoactive compounds. High boiling solvents and ketone catalysts have been employed to facilitate the decarboxylation of tryptophan.

Analytical chemistry of synthetic routes to psychoactive tryptamines. Part III. Characterisation of the Speeter and Anthony route to N,N-dialkylated tryptamines using CI-IT-MS-MS.

Twelve symmetrically and 13 asymmetrically N,N-disubstituted glyoxalylamide precursors and their corresponding tryptamine derivatives have been characterised by gas chromatography low-pressure chemical ionisation ion trap tandem mass spectrometry (CI-IT-MS-MS) with internal (in situ) ionisation using methanol as the chemical ionisation reagent. Mass spectral differences and similarities between the investigated compounds are discussed and put into context with previous investigations. In tryptamines the formation of [CH2=N+R2R3] iminium ions after beta-cleavage appears to be the dominating process.

Analytical chemistry of synthetic routes to psychoactive tryptamines. Part II. Characterisation of the Speeter and Anthony synthetic route to N,N-dialkylated tryptamines using GC-EI-ITMS, ESI-TQ-MS-MS and NMR.

The degree of alkylation of the side chain nitrogen in tryptamines is one important factor that affects psychoactivity. The method of Speeter and Anthony is considered to be one of the most important synthetic preparative methods. The final step in this reaction is based on the reduction of a (substituted) indole-3-yl-glyoxalylamide to the desired tryptamine with metal hydride.

Mammary uptake and excretion of prostanoids in relation to mammary blood flow and milk yield during pregnancy-lactation and somatotropin treatment in dairy goats.

Mammary arterious-venous differences (A-V) and excretion into milk of four prostanoids were related to changes in milk yield and milk vein blood velocity (MBV) in goats at different stages of pregnancy and lactation, and during somatotropin (ST) treatment in mid-lactation. Arterial concentrations and mammary A-V for the vasodilators prostacyclin (PGI(2)) and prostaglandin (PG) E(2) (measured as 6-keto-PGF(1 alpha) and bicyclic PGE(2), respectively) decreased from late pregnancy to lactation. A-V were negatively correlated to MBV (r = -0.

Analytical chemistry of synthetic routes to psychoactive tryptamines. Part I. Characterisation of the Speeter and Anthony synthetic route to 5-methoxy-N,N-diisopropyltryptamine using ESI-MS-MS and ESI-TOF-MS.

5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT), a new psychoactive tryptamine derivative, has been synthesised by the Speeter and Anthony procedure. This synthetic route was characterised by ESI-MS-MS, ESI-TOF-MS and NMR. Side products have been identified as 3-(2-N,N-diisopropylamino-ethyl)-1H-indol-5-ol (5), 2-N,N-diisopropylamino-1-(5-methoxy-1H-indol-3-yl)-ethanol (6), 2-(5-methoxy-1H-indol-3-yl)-ethanol (7) and 2-N,N-diisopropylamino-1-(5-methoxy-1H-indol-3-yl)-ethanone (8).

The effects of relaxin on the response of intramammary pressure and mammary blood flow to exogenous oxytocin in the goat.

Lactating goats were given relaxin (50 micrograms) by close-arterial infusion into one mammary gland. The increase in intramammary pressure and in mammary blood flow elicited by exogenous oxytocin i.v.

Blood prolactin concentrations affect prolactin transfer into goat milk: implications for maintenance of lactation.

125I-Labelled ovine prolactin was infused for 15 min into a pudic artery supplying one mammary gland of lactating goats (n = 17). Between 0 and 4.25 h significantly more total (P < 0.

The local differential effect of prostacyclin, prostaglandin E2 and prostaglandin F2 alpha on mammary blood flow of lactating goats.

Mammary blood flow (MBF) and milk yield are closely related in dairy ruminants, but little is known about the regulation of MBF in vivo. The local effects on MBF of injections or continuous infusions into the mammary artery of prostaglandins (PG) or indomethacin (an inhibitor of prostaglandins) respectively, were investigated in surgically prepared conscious goats. Prostacyclin (PGI2) was found to be a potent stimulator of MBF which increased linearly over the dose range 50-1000 ng.

Unilateral control of ovarian oxytocin release and the facilitatory effects of insulin-like growth factor-I in sheep.

Prostaglandin F2 alpha (PGF2 alpha)-induced release of ovarian oxytocin was investigated to determine whether the effect in vivo was local. [3H]PGF2 alpha infused downstream into a single ovarian lymphatic was transferred into the adjacent ovarian vasculature (estimated transfer 1.1 and 1.

Transfer of insulin-like growth factors I and II from plasma to lymph in young goats.

The plasma clearance of intravenously injected 125I-labelled insulin-like growth factor I (IGF-I, n = 13) and IGF-II (n = 12) and their transfer into lymph draining the foreleg of 3.5- to 8-week-old British Saanen goats was studied. Both peptides were initially distributed into a volume equivalent to the plasma volume, while the final distribution spaces for IGF-I and IGF-II were 90 +/- 9.

Secretion of insulin-like growth factor II into milk.

125I-labeled insulin-like growth factor II (IGF-II) was infused directly into the pudic artery supplying one gland of lactating goats (n = 4). Maximum specific activity for [125I]IGF-II transferred into milk from the infused gland was reached 60 min after that in plasma and was 2.5 fold greater than in milk from the non-infused gland.

Mechanism of secretion of plasma insulin-like growth factor-I into milk of lactating goats.

125I-Labelled insulin-like growth factor-I (IGF-I) was infused as the free form directly into the pudic artery supplying one gland of lactating goats (n = 6). The infusion was for 60 min and 0.4 +/- 0.

The galactopoietic effect of bovine growth hormone in goats is associated with increased concentrations of insulin-like growth factor-I in milk and mammary tissue.

Lactating goats exhibiting widely divergent responses to short-term (4 days) treatment with bovine GH (bGH) were retrospectively divided into two groups based on the magnitude of this response. There was no difference between groups in terms of the pretreatment milk yield, but by day 4 of treatment milk secretion had increased by 4.99 +/- 2.

Increase in milk secretion and mammary blood flow by intra-arterial infusion of insulin-like growth factor-I into the mammary gland of the goat.

The close-arterial infusion of free insulin-like growth factor-I (IGF-I; 1.1 nmol/min) for 6 h into the pudic artery supplying one mammary gland of lactating goats caused a 25 +/- 6% (mean +/- S.E.

Neurotransmitters and lymphatic-vascular transfer of prostaglandin F2 alpha stimulate ovarian oxytocin output in sheep.

The mechanisms of lymphatic-vascular transfer across the ovarian vascular pedicle were studied in anaesthetized sheep 8-15 days after ovulation. [3H]Prostaglandin F2 alpha (PGF2 alpha), [14C]mannitol and [36Cl]Na were infused continuously into either a uterine lymphatic or a uterine vein and the kinetics of transfer into the adjacent utero-ovarian vein or ovarian plasma were studied. Transfer occurred according to the sequence [36Cl] greater than [14C] greater than [3H] indicating that PGF2 alpha is not transferred by rapid diffusion, as with [36Cl]Na, nor by a paracellular route, as with [14C]mannitol, but by a slower process probably involving facilitated diffusion.

Cardiovascular responses and mammary substrate uptake in Jersey cows treated with pituitary-derived growth hormone during late lactation.

Pituitary-derived bovine growth hormone (bGH) was administered to Jersey cows during late lactation for 7 d. Milk yield increased significantly during treatment and by a maximum of 49.6% on d 7.

Increased secretion of insulin-like growth factor I into milk of cows treated with recombinantly derived bovine growth hormone.

Six lactating, non-pregnant Jersey cows were given subcutaneous injections of recombinantly derived bovine growth hormone for 7 d. Milk yield was increased by 4.5 kg/d on d 7, compared with the average yield of 10.

From animal to molecule: aspects of the biology of insulin-like growth factors.

The synthesis of IGF-II mRNA in sheep foetal tissues is considerably higher than IGF-I. IGF-II probably has a paracrine role in the foetus; however it is likely that IGF-I originates mainly from the foetal liver and has an endocrine function. Although in the adult system IGF-I is tightly bound to serum carrier proteins it is potentially biologically active.

Cardiovascular and metabolic responses during growth hormone treatment of lactating sheep.

Pituitary-derived bovine growth hormone (bGH) was administered to six lactating Friesland ewes for 7 d. There was no consistent galactopoietic response, with changes in milk yield varying from 0 to 33% during treatment compared with the pretreatment period. The major effect of bGH on the concentration of milk constituents was to increase fat by 14.

Protein synthesis and degradation in the mammary gland of lactating goats.

Lactating goats were given a close arterial infusion of [1-14C]leucine and [4,5-3H]4-methyl-2-oxopentanoic acid into one half of the mammary gland at 2-3 weeks and 34-39 weeks after kidding. Rates of protein synthesis, degradation and net output were determined from measurements of arteriovenous difference and blood flow using a model of leucine metabolism previously developed for muscle (Oddy & Lindsay, 1986). Protein leucine output in milk (Y mumol/min) correlated well with the difference between synthesis and degradation (X mumol/min) derived from the model: Y = 1.

Suppression by perchlorate of technetium-99m and iodine-123 secretion in milk of lactating goats.

Lactating goats were infused with either technetium-99m (99mTc) or iodine-123 (123I) together with chlorine-36 (36Cl) through an indwelling catheter previously placed in an external pudic mammary artery. The radioisotope infusions were repeated together with 100 mg of sodium perchlorate. There was a rapid transfer of 99mTc and 123I into milk, reaching a peak concentration 30 min after a 15-min infusion.