Search results for "pine"

Day-night differences in the sensitivity of adrenoceptors in the Syrian hamster pineal gland: an in vivo iontophoretic study.

1989

Abstract Investigations on the regulation of pineal melatonin synthesis in the Syrian hamster revealed distinct differences compared to this well-understood mechanism in rat. E.g., a circadian profile of pineal norepinephrine (NE) is absent, there is no β-adrenoceptor sensitivity during daytime and adrenergic receptor supersensitivity is not easily achieved. To elucidate the action of NE on pineal receptor sites, the effects of iontophoretic application of adrenergic compounds on spontaneous electrical discharge rates of pinealocytes were investigated during day- and nighttime. Following application of either NE, isoproterenol or clonidine, cells were activated, inhibited or not affected. W…

A muscarinic mechanism inhibiting the release of noradrenaline from peripheral adrenergic nerve fibres by nicotinic agents.

1968

Changes in the Three Dimensional Structure of Synaptic Ribbons in the Pineal Gland of the Guinea-Pig Caused by Constant Light

1997

Synaptic bodies (SBs) are dynamic synaptic organelles of afferent synapses of the retina, inner ear, lateral line organ and pineal gland in vertebrates. When investigated in a transmission electron microscope, their electron-dense rod-like, round or irregular profiles are surrounded by electron-lucent vesicles. The three-dimensional structure of pineal SBs is not precisely known. Pineal glands of two guinea-pigs (one kept under an LD cycle of 12:12 h; one kept in constant light for 8 weeks) were investigated. SBs were reconstructed in three dimensions to visualise morphological changes in constant light. Transmission electron microscope micrographs from up to 18 serial sections with a known…

Circadian and Infradian Activity Rhythms in the Mammalian Pineal Body

1982

The neuroendocrine nature of the pineal organ is well established. Linked to the optic system via postganglionic sympathetic fibres coming from the superior cervical ganglia, the parenchymal cells of the pineal synthesize serotonin from tryptophan and convert it to melatonin, the most widely studied pineal substance, and other indoleamines. Melatonin synthesis is stimulated by noradrenaline released from intrapineal sympathetic nerve fibres, involving β-adrenergic mechanisms and the adenyl cyclase-cAMP-system. The rate-limiting enzyme of melatonin formation is serotonin-N-acetyltransferase (NAT) that converts serotonin to N-acetylserotonin. Hydroxyindole-O-methyltransferase (HIOMT) catalyze…

Thirty years of synaptosome research.

1993

Detached synapses (synaptosomes), first isolated by the author in 1958 and identified as such in 1960, are sealed presynaptic nerve terminals often with a portion of the target cell--sometimes amounting to a complete dendritic spine--adhering to their external surface. They can be prepared in high yield from brain tissue and also in decreasing yield from spinal cord, retina, sympathetic ganglia, myenteric plexus and electric organs. They are sealed structures which, under metabolizing conditions, respire, take up oxygen and glucose, extrude Na+, accumulate K+, maintain a normal membrane potential and, on depolarization, release transmitter in a Ca(2+)-dependent manner. They thus provide an …

No invasive methodology to produce a probiotic low humid apple snack with potential effect against Helicobacter pylori

2012

Abstract A probiotic low humid apple snack with potential effect against the infection caused by Helicobacter pylori has been developed from apple (cv. Granny Smith) and mandarin juice with a high microbial content of Lactobacillus salivarius spp . salivarius , by vacuum impregnation and hot air drying techniques. The moisture content reached in the final product (0.144 ± 0.012  g water · g sample - 1 ) ensured stability, and although the drying process affected the microbial content, the concentration in the final product (9.486 ± 0.013) × 10 7  CFU  g dry sample - 1 ) was sufficient to confirm that with this procedure it is possible to obtain a stable probiotic fruit with a low moisture c…

Vegetation of solid rock faces and fissures of the alpine and subnival zone in the Pamir Alai Mountains (Tajikistan, Middle Asia)

2014

The paper presents results of phytosociological researches on rock faces vegetation of Pamir Alai Mountains. In total, 182 phytosociological relevés were made during the field studies conducted in 2006–2012, applaying the Braun-Blanquet method. Plant communities of calcareous firm rock faces and small fissures, inhabiting mainly the alpine and subnival zone in several ranges (e.g. Zeravshan Mts, Hissar Mts, Hazratishoh Mts, Darvaz Mts, Rushan Mts and Vanch Mts) are herein described for the first time. A hierarchical syntaxonomic synopsis of the rock communities of the Pamir Alai is provided. The collected vegetation samples represent the majority of the variability among the phytocoenoses o…

Vegetation of taluses and screes of the high montane and alpine zone in the Pamir Alai Mountains (Tajikistan, Middle Asia)

2015

This paper presents the results of phytosociological research on scree vegetation of the Pamir Alai Mts. In total, 128 phytosociological relevés were made during field studies conducted in 2012–2014, applying the Braun-Blanquet method. Plant communities of mobile and fairly stabilised scree of colluvial cones, aprons and fans, inhabiting mainly the high montane and alpine zone in several ranges (e.g.the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan and Vanch Mts) are herein described. A hierarchical syntaxonomic synopsis of scree communities at montane and alpine elevations in the Pamir Alai Mts is provided. The collected vegetation samples represent the majority of the variations among th…

Vegetation Diversity of Screes and Taluses of The Pamir and South-Western Tian Shan in Middle Asia

2021

AbstractThis paper presents the results of phytosociological research on scree vegetation of the Pamir and south-western Tian Shan. We collected 222 phytosociological relevés during field studies conducted in 2015–2019, applying the Braun-Blanquet approach. We identified 21 plant communities on mobile and stabilized screes of colluvial cones, aprons and fans, inhabiting mainly the montane and alpine belts in several ranges (e.g. Peter the First, Alichur, Shugnan, Shachdarian, Darvaz, Rushan, Vanch, Fergana, Kyrgyz and Terskey ranges). As a result we provide the first comprehensive hierarchical syntaxonomic synopsis of scree communities at montane and alpine elevations in the eastern Middle …

Diversity, distribution, and classification of chasmophytic vegetation in the Central Asian biodiversity hotspot : alpine belt of the Eastern Pamir-A…

2022

AbstractThis paper presents the results of research conducted on chasmophytic vegetation occurring within the alpine belt (approx. 1,850–4,000 m a.s.l.) in the eastern part of Middle Asia. We specifically focused on the diversity and syntaxonomy of rock vegetation as well as on environmental variables determining its distribution. Altogether, 242 relevés were sampled in rock fissures, ledges, and clefts during field surveys conducted in 2013–2019. The size of each recorded vegetation plot was 1 m2. Five main groups of chasmophytic vegetation were distinguished in the studied area. Each group was confined to a specific combination of substrate type and climatic conditions. Altogether, 16 spe…