Relationship between seasonal patterns of platelet serotonin uptake and 3H-imipramine binding in depressed patients and normal controls

Platelet serotonin-binding and dexamethasone suppression test in melancholia and dysthymia

“…Most of the studies on serotonergic function in platelets have focused on imipramine-binding and on the maximum 5HT uptake (usually called V max ), a kinetic parameter that measures the ability of the carrier of 5HT to transport it into platelets. These studies have usually found a decrease in V (Tuomisto and Tukiainen, 1976;Meltzer et al, 1981;Chicz-Demet et al, 1991). The present study, focused on the 3 H-5HT bindi ng, suggests a decrease of the number of 5HT-binding sites in melancholic patients.…”

“…They showed that the high-affinity binding site for Tl-imipramine in brain and platelet membranes was functionally associated with the 5HT uptake or transport site, and suggested that this finding supported the fact that the imipramine binding site is an integral component of the outer membrane portion of the 5HT transporter. Recently, Chicz-Demet et al (1991) have found a close relationship between 5HT uptake and -'H-imipramine-binding in depressed patients, suggesting that the Ul-iinipramine-binding site may be closely associated, or identical to a 5HT transport carrier. However, as it has been previously said, some data suggest that the 3 H-imipramine-binding site could represent a modulatory receptor separate from the substrate recognition site of the carrier (Langer and Schoemaker, 1988).…”

Platelet serotonin-binding and dexamethasone suppression test in melancholia and dysthymia

“…Most of the studies on serotonergic function in platelets have focused on imipramine-binding and on the maximum 5HT uptake (usually called V max ), a kinetic parameter that measures the ability of the carrier of 5HT to transport it into platelets. These studies have usually found a decrease in V (Tuomisto and Tukiainen, 1976;Meltzer et al, 1981;Chicz-Demet et al, 1991). The present study, focused on the 3 H-5HT bindi ng, suggests a decrease of the number of 5HT-binding sites in melancholic patients.…”

“…They showed that the high-affinity binding site for Tl-imipramine in brain and platelet membranes was functionally associated with the 5HT uptake or transport site, and suggested that this finding supported the fact that the imipramine binding site is an integral component of the outer membrane portion of the 5HT transporter. Recently, Chicz-Demet et al (1991) have found a close relationship between 5HT uptake and -'H-imipramine-binding in depressed patients, suggesting that the Ul-iinipramine-binding site may be closely associated, or identical to a 5HT transport carrier. However, as it has been previously said, some data suggest that the 3 H-imipramine-binding site could represent a modulatory receptor separate from the substrate recognition site of the carrier (Langer and Schoemaker, 1988).…”

Circadian and circannual rhythms in the function of central 5-HT 1A receptors in laboratory rats

“…maximum velocity of the platelet 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), or changes in B max of platelet imipramine binding (Egrise et al 1986;Healy et al 1990;DeMet et al 1990DeMet et al , 1991Chicz-Demet et al 1991), but the wave-forms are entirely di¤erent among di¤erent authors. Such disagreements among authors may also be resolved by experiments that take into account the possibility that the wave-forms of circannual rhythms are di¤erent according to the time of day.…”

“…In healthy persons, 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), imipramine binding (Egrise et al 1986;DeMet et al 1990DeMet et al , 1991Healy et al 1990;Chicz-Demet et al 1991), and paroxetine binding (Klompenhouwer et al 1990;DHondt et al 1994) in platelets, 5-HT (Sarrias et al 1989), 5-HIAÀ (Sarrias et al 1989), and L-tryptophan (Maes et al 1995) in plasma, 5-HIAA in cerebrospinal ßuid (Brewerton et al 1988), and 5-HT in brain tissue examined post-mortem (Carlsson et al 1980) exhibit seasonal variations. Many reports have conÞrmed that birth (Hare et al 1974;Rihmer 1980), hospital admissions (Rihmer 1980;Parker and Walter 1982;Takei et al 1992), and the severity (Maes et al 1993a) of depression or the incidence of suicide (Maes et al 1993b;Barker et al 1994), which are thought to be etiologically related to dysfunction of the 5-HT system, demonstrate seasonal variations.…”

Platelet serotonin-binding and dexamethasone suppression test in melancholia and dysthymia

“…Most of the studies on serotonergic function in platelets have focused on imipramine-binding and on the maximum 5HT uptake (usually called V max ), a kinetic parameter that measures the ability of the carrier of 5HT to transport it into platelets. These studies have usually found a decrease in V (Tuomisto and Tukiainen, 1976;Meltzer et al, 1981;Chicz-Demet et al, 1991). The present study, focused on the 3 H-5HT bindi ng, suggests a decrease of the number of 5HT-binding sites in melancholic patients.…”

“…They showed that the high-affinity binding site for Tl-imipramine in brain and platelet membranes was functionally associated with the 5HT uptake or transport site, and suggested that this finding supported the fact that the imipramine binding site is an integral component of the outer membrane portion of the 5HT transporter. Recently, Chicz-Demet et al (1991) have found a close relationship between 5HT uptake and -'H-imipramine-binding in depressed patients, suggesting that the Ul-iinipramine-binding site may be closely associated, or identical to a 5HT transport carrier. However, as it has been previously said, some data suggest that the 3 H-imipramine-binding site could represent a modulatory receptor separate from the substrate recognition site of the carrier (Langer and Schoemaker, 1988).…”

Circadian and circannual rhythms in the function of central 5-HT 1A receptors in laboratory rats

“…maximum velocity of the platelet 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), or changes in B max of platelet imipramine binding (Egrise et al 1986;Healy et al 1990;DeMet et al 1990DeMet et al , 1991Chicz-Demet et al 1991), but the wave-forms are entirely di¤erent among di¤erent authors. Such disagreements among authors may also be resolved by experiments that take into account the possibility that the wave-forms of circannual rhythms are di¤erent according to the time of day.…”

“…In healthy persons, 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), imipramine binding (Egrise et al 1986;DeMet et al 1990DeMet et al , 1991Healy et al 1990;Chicz-Demet et al 1991), and paroxetine binding (Klompenhouwer et al 1990;DHondt et al 1994) in platelets, 5-HT (Sarrias et al 1989), 5-HIAÀ (Sarrias et al 1989), and L-tryptophan (Maes et al 1995) in plasma, 5-HIAA in cerebrospinal ßuid (Brewerton et al 1988), and 5-HT in brain tissue examined post-mortem (Carlsson et al 1980) exhibit seasonal variations. Many reports have conÞrmed that birth (Hare et al 1974;Rihmer 1980), hospital admissions (Rihmer 1980;Parker and Walter 1982;Takei et al 1992), and the severity (Maes et al 1993a) of depression or the incidence of suicide (Maes et al 1993b;Barker et al 1994), which are thought to be etiologically related to dysfunction of the 5-HT system, demonstrate seasonal variations.…”

Platelet serotonin-binding and dexamethasone suppression test in melancholia and dysthymia

“…Most of the studies on serotonergic function in platelets have focused on imipramine-binding and on the maximum 5HT uptake (usually called V max ), a kinetic parameter that measures the ability of the carrier of 5HT to transport it into platelets. These studies have usually found a decrease in V (Tuomisto and Tukiainen, 1976;Meltzer et al, 1981;Chicz-Demet et al, 1991). The present study, focused on the 3 H-5HT bindi ng, suggests a decrease of the number of 5HT-binding sites in melancholic patients.…”

“…They showed that the high-affinity binding site for Tl-imipramine in brain and platelet membranes was functionally associated with the 5HT uptake or transport site, and suggested that this finding supported the fact that the imipramine binding site is an integral component of the outer membrane portion of the 5HT transporter. Recently, Chicz-Demet et al (1991) have found a close relationship between 5HT uptake and -'H-imipramine-binding in depressed patients, suggesting that the Ul-iinipramine-binding site may be closely associated, or identical to a 5HT transport carrier. However, as it has been previously said, some data suggest that the 3 H-imipramine-binding site could represent a modulatory receptor separate from the substrate recognition site of the carrier (Langer and Schoemaker, 1988).…”

Circadian and circannual rhythms in the function of central 5-HT 1A receptors in laboratory rats

“…maximum velocity of the platelet 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), or changes in B max of platelet imipramine binding (Egrise et al 1986;Healy et al 1990;DeMet et al 1990DeMet et al , 1991Chicz-Demet et al 1991), but the wave-forms are entirely di¤erent among di¤erent authors. Such disagreements among authors may also be resolved by experiments that take into account the possibility that the wave-forms of circannual rhythms are di¤erent according to the time of day.…”

“…In healthy persons, 5-HT uptake (Arora et al 1984;Egrise et al 1986;Malmgren et al 1989;Marazziti et al 1990;Chicz-Demet et al 1991), imipramine binding (Egrise et al 1986;DeMet et al 1990DeMet et al , 1991Healy et al 1990;Chicz-Demet et al 1991), and paroxetine binding (Klompenhouwer et al 1990;DHondt et al 1994) in platelets, 5-HT (Sarrias et al 1989), 5-HIAÀ (Sarrias et al 1989), and L-tryptophan (Maes et al 1995) in plasma, 5-HIAA in cerebrospinal ßuid (Brewerton et al 1988), and 5-HT in brain tissue examined post-mortem (Carlsson et al 1980) exhibit seasonal variations. Many reports have conÞrmed that birth (Hare et al 1974;Rihmer 1980), hospital admissions (Rihmer 1980;Parker and Walter 1982;Takei et al 1992), and the severity (Maes et al 1993a) of depression or the incidence of suicide (Maes et al 1993b;Barker et al 1994), which are thought to be etiologically related to dysfunction of the 5-HT system, demonstrate seasonal variations.…”